HomeMy WebLinkAboutRiverfrontCrossings_Draft_Highres.4.21.11iowa city. ia
april. 2011
riverfront crossings district
sub-area plan
DRAFT
Executive Summary
Project Background
Analysis
Site Context
Physical Features
Natural Features
Sub-Area Plan
Planning Workshop
Plan
Framework Elements
Mobility
Green Space
Stormwater BMPs
Design Guidelines
Land Use
Heights
Frontages and Setbacks
Parking and Access
Special Requirements
Block Analysis
Development Block Diagrams
Next Steps
Appendices
Appendix A: Auto-Oriented Uses
Appendix B: Conceptual Transportation Analysis
1
3
5
6
8
9
11
12
14
17
18
22
25
33
34
36
38
40
42
45
46
59
61
62
63
1
executive summary
DRAFT riverfront crossings sub-area plan2
executive summary
In 2010 Iowa City was one of only five communities across
the country selected by EPA through a competitive process as
a Brownfield Pilot as part of the Partnership for Sustainable
Communities. The Partnership for Sustainable Communities is a
joint venture of the U.S. Environmental Protection Agency (EPA),
U.S. Department of Housing and Urban Development (HUD),
and U.S. Department of Transportation (DOT) based on “livability
principles” that guide inter-agency collaboration and support
the integration of safe, reliable and economical transportation;
affordable, energy-efficient housing; and sustainable reuse of idle
or underutilized land. Designation as a pilot provided technical
assistance to expand on previous planning efforts to create a more
detailed plan for a sub-area of the larger Riverfront Crossings
District, just south of Downtown Iowa City.
This Sub-Area Plan is based on six key project goals that represent
a holistic approach to the redesign and redevelopment of the study
area. • Develop a new mixed-use, pedestrian-oriented district
• Create a resilient riverfront park system • Enhance Ralston Creek to become a community asset • Develop a multi-modal transportation network • Create a network of green streets in the district • Promote sustainable design practices within the district
The study area encompasses roughly 80 acres in the southern
portion of the district and is bounded by U.S. Highway 6 on the
south, the Iowa River on the west, the Interstate Rail Line on the
north and the Cedar Rapids and Iowa City (CRANDIC) Rail Line on
the east. Currently a low-density, auto-oriented district, the goal
is to transition the area over time to a more pedestrian-oriented,
mixed-use neighborhood, with a new riverfront park and a highly
connected mobility network.
Large portions of the study area were inundated by flooding in
2008, including the City’s North Wastewater Treatment Plant, which
is located adjacent to the Iowa River. Plans are for the treatment
plant to be relocated and its site transformed into a riverfront park
designed to help absorb flood waters and provide a variety of
public multi-use spaces, trails, and access to the river. The riverfront
park will also become a catalyst for redevelopment of the district.
The east side of the park is bordered by Ralston Creek. Most existing
development in this area has turned its back on the creek, which
has been degraded over time by polluted urban runoff. Opening
up the creek, using ‘soft’ bank stabilization methods, and restoring
riparian habitat will help enhance Ralston Creek as a community
amenity.
The goal for the Riverfront Crossings District is to transform it into
a prototype for sustainable stormwater management. As such, a set
of conceptual stormwater best management practices (BMPs) was
created to help define areas that have potential applicability for
providing on-site treatment of runoff.
The potential for high-speed rail and light-rail service within
the Riverfront Crossings District provides the foundation for an
interconnected mobility network. The Rock Island Station, located
just north of the study area, is a possible stop on the high-speed
rail connection to Chicago. Two stops for light-rail (which would
ultimately connect to Cedar Rapids) are also proposed in the study
area. An expanded bus network, new on-street and off-street bike
facilities, and a highly connected vehicular and pedestrian network
will give residents and visitors a variety of options for sustainable
modes of transportation.
The Riverfront Crossings Sub-Area will also be developed as a
pedestrian-oriented, mixed-use neighborhood. Gilbert Street is
a major north/south corridor in Iowa City and will become an
attractive place for mixed-use development with ground-floor
commercial. As Ralston Creek is restored and becomes an amenity
for the community, residential buildings will be constructed to
overlook the creek and the riverfront park. The southern portion of
the study area, along Gilbert Street, is located within the flight zone
of the Iowa City Municipal Airport and will be subject to Federal
Aviation Administration (FAA) height restrictions. The northern
portion of the study area is located outside the height restrictions
and has the potential to be developed with higher-density blocks.
Proposed residential towers in this area will take advantage of
views overlooking the riverfront park and the Iowa River corridor.
Housing typologies proposed for the area will be attractive to a
range of household types and income levels.
Design guidelines will guide development of the Riverfront
Crossings Sub-Area and establish standards that are intended
to help create the mixed-use, pedestrian-oriented community
envisioned. These standards primarily look at form, function, and
features of buildings that define and shape the public realm. They
are composed of guidelines for land use, building height, frontages
and setbacks, parking and access, and special requirements.
3
project background
DRAFT riverfront crossings sub-area plan4
project background
In 2009, as a part of post-flood recovery efforts, Iowa City received
a grant of technical assistance through the U.S. Environmental
Protection Agency’s (EPA) Smart Growth Assistance Program.
The City worked with EPA representatives and private planning
consultants to survey the neighborhood, interview property and
business owners and other stakeholders, and conduct several
public input sessions. Through this process, the EPA and its
planning consultants compiled the research and public input from
which they drafted a number of policy recommendations relating
to future economic development potential, changes to land use
and urban form, and enhancements to transportation options
for the area. An overview of these policy recommendations is
summarized below.
Final Market Overview
ICF International. 12/11/2009
• Iowa City has experienced some of the most stable market
conditions across the country, mostly because it is a recession-
resistant college town.• Iowa City is consistently ranked as one of the best places in
America to live, and the large University enrollment translates
into increased housing and consumer market demand. • Although funding is uncertain, there is the future potential for
both high-speed rail and light-rail within the district. Future stops
would make this district ideal for transit-oriented development
(TOD) that could support high density mixed-use development. • Proposed Riverfront Crossings District redevelopment will offer a
mixed-income, mixed-use, transit-oriented, urban neighborhood
that will likely appeal to various segments of the young
professional market.
• The “creative class”, the young professionals age 25-34 who are
attracted to high-density, affordable, urban living, will be drawn
to amenities such as transit accessibility, proximity to cultural
activities, downtown, and open space. • The region will continue to grow more quickly than the state and
will add an average of 1,064 new households to the residential
market annually. The number of households is growing faster
than the overall population growth. • The Riverfront Crossings District will likely have apartment-
style condominiums because of the current lack of for-sale units
targeted towards young professionals.• It is likely that downtown expansion, because of the growth of
professional jobs and University expansion plans, will occur south
of downtown into the Riverfront Crossings District. • The Riverfront Crossings District is considered to be a less
expensive alternative to downtown, and using it to establish
affordable housing is very important to the community.• Marketek estimates that from 2007-2017, Downtown Iowa City
has a potential to absorb approximately 2,257 units of market rate
for-sale and rental housing.• By 2017, an additional 800,000 SF of retail space could be
supported by population increases in the greater market area. The
Riverfront Crossings area should expect to capture some of this. • Not all development in Riverfront Crossings should be required to
be mixed-use.• Because of the daily workforce population currently within the
district, there is existing but untapped local-neighborhood
demand for commercial services.
Final Transportation Policy Options
Nelson/Nygaard Consulting Associates. 01/06/2010
• Policy Options:
›Improve transportation network connectivity and
comprehension ›Complete all district streets ›Implement a road diet on Gilbert by converting it into a three-
lane roadway with center turn-lane and on-street parking
›Revert one-way streets back to two-way streets ›Expand or reroute circulator to serve Riverfront Crossings
District ›Brand high quality transit offerings ›Fund and implement station area development and access
plans ›Price parking to ensure curb-space availability ›Create a universal transit pass program ›Implement a local car sharing program ›Transit service and facility policy options
›Transportation demand management options ›Additional parking policy options -Create a neighborhood parking permit system -Redefine parking demand as access demand -Expand parking maximums
-Implement a parking cash out program -Require and support shared parking facilities
›Additional bicycling policy options -Improve on-street bicycle facilities -Include bicycle facilities in intersection improvements -Expand bicycle parking requirements for new development
-Improve bicycle parking -Provide end-of-trip facilities and services -Consider implementing pilot programs
Policy Options
Dover, Kohl, & Partner. 01/15/2010
• Policy options with regard to planning and urban design issues
within the Riverfront Crossings District include: ›Create a resilient riverfront park system ›Enhance Ralston Creek ›Establish community gardens in the Riverfront Crossings
District ›Create new mixed-use zoning with design provisions for
Riverfront Crossings ›Draft and adopt a form-based code ›Seek a range of affordable housing types and diverse business
in Riverfront Crossings ›Encourage small-scale, sustainable energy production ›Encourage innovative stormwater management ›Create a network of green streets in Riverfront Crossings ›Improve streetscapes within Riverfront Crossings and plant
more trees ›Brand Riverfront Crossings as a “green district” ›Establish an updated, design-driven vision for Riverfront
Crossings
MEMORANDUM To: Matt Dalbey, EPA
From: Amy Doll, ICF WAM, and Elizabeth Johnston, ICF
Date: December 11, 2009 Re: WA 4-47 Task 5 Final Market Overview Memo for Iowa City Deliverable 5c Introduction This memo summarizes the market conditions in the Riverfront Crossings District, exploring, in particular, opportunities for residential and mixed-use commercial development. This summary can be used to provide market context and background information needed to facilitate informed discussions with key stakeholders as Iowa City’s planning effort progresses. As a summary document, this memo relies mainly on secondary sources for demographic, land use and market analysis data. While some of the data reviewed was assembled two years ago1, Iowa City has experienced some of the most stable market conditions across the country, in part because it is a recession-resistant college-town, with a captive market2. Current market conditions and land use patterns were confirmed by discussions with the Iowa City Planning Department and the community workshops that occurred November 11 – 13, 2009. The context for this market assessment is two-part. Riverfront properties in the Riverfront Crossings District were devastated by the floods of 2008, making redevelopment mandatory. These floods and subsequent destruction led planners to reassess the risks of development within the floodplain. It is likely that properties at high flood risk will be rezoned as open space and left undeveloped to minimize future potential damage. This redevelopment presents a unique opportunity to develop new neighborhood park-land and design an amenity-rich community that will appeal to existing residents, employers and employees as well as attract new residential and commercial opportunities. In addition to necessary redevelopment due to flooding, the district has become a focal point in discussions regarding transit-oriented development (TOD) in Iowa City. If additional funding is secured from the State, an Amtrak station could be located in the district in the historic Rock Island Railroad Depot. This station would provide rail access to Chicago and other major cities throughout the Midwest. In addition to the Amtrak station, there is an opportunity to provide access to local passenger rail in the Iowa City/Cedar Rapids region, through the creation of two transit stops in the district. The CRANDIC rail line is ideally located to provide service from the heart of the district to the University campus, the University and Veterans hospitals, and
1 Much of the market analysis data is from reports/analysis conducted in 2007 and the latest census data available is from 2007 as well 2 Evens, Kelly. Why College Towns Are Looking Smart, Wall Street Journal, March 24, 2009 - 1 -
M E M O R A N D U M To: Amy Doll, ICF WAM From: Justin Falango, DKP Date: January 15, 2010 Subject: Policy Options Memorandum (Deliverable 5a) Riverfront Crossings District – Iowa City, Iowa This memorandum presents a summary of development policy options with regard to planning and urban design issues within the Riverfront Crossings District of Iowa City. These address specific local issues while serving as a case study for other communities who are hoping to use smart growth approaches as part of their recovery from natural disasters, such as the flooding which occurred in Iowa City in 2008. The policies summarized in this memo dovetail with those already outlined in the Final Transportation Policy Options Memorandum of January 6, 2010 and the Final Market Overview Memorandum of December 11, 2009. These policy options were explored and refined following the Iowa City Smart Growth Workshop from November 11 -13, where feedback from stakeholders, city staff, and the community was gathered. POLICY OPTIONS These policy options were explored in depth during the workshop and all generally supported by the community and the City. Create a Resilient Riverfront Park System The mechanisms of absorption and evapotranspiration makes trees essential in mitigating stormwater runoff and even hasten the drying of waterlogged earth after major floods. Careful grading and landscaping of the floodplain into a riverfront park system, planted with native trees, shrubs, and grasses that can survive standing water will provide some degree of protection during floods. These newly created park spaces will serve as a community amenity which will evolve and improve over time. They may contain recreational facilities, walking/biking trails, designated fishing areas, ornamental/food gardens, and preserve areas. The community was very excited about creating a system of new park spaces along the riverfront and making use of flood-prone areas for civic purposes. Sixty percent of respondents to the exit questionnaire chose the riverfront park system as one of five ideas they were most excited about – the largest number recorded. Polling at the closing presentation also showed that eighty-two
621 SW Morrison Street, Suite 950 Portland, Oregon 97205 (503) 227-3463 FAX: (503) 228-2320 M E M O R A N D U M
To: Amy Doll, ICF WAM
From: Thomas Brennan
Date: January 6, 2010
Subject: Final Transportation Policy Options Memorandum (deliverable 5b)
The purpose of this memorandum is to present policy options and potential transportation improvements for the Riverfront Crossings District that will address specific local issues while serving as a Smart Growth case study for other communities recovering from natural disaster. The memo presents an overview of the study area, a review of relevant studies, and specific transportation policy options. The included policy options have been developed and vetted through consultant review of local conditions, on site meetings with staff and stakeholders, and a series of public meetings held in Iowa City during November 2009.
I. Introduction
This section provides an overview of the Riverfront Crossings District and its related redevelopment efforts.
Overview of Study Area
The Riverfront Crossings District is bounded by Burlington Street / State Highway 1 on the north, State Highway 6 on the south, South Van Buren / Boyrum Streets on the east, and the Iowa River on the west. There are two Iowa City designated planning districts that fall within the Riverfront Crossings District: the Near Southside (to the north) and the Central District to the south. The Near Southside is north of the Iowa Interstate Railroad, south of Iowa City Central Business District and adjacent to the University of Iowa campus. The southern part of the study area, between the Iowa Interstate Railroad and Highway 6, lies in the Central District. (See Figure 1).
The study area houses a broad mix of land uses, ranging from single-family to high-density residential, office, commercial, warehouse / light industrial, and public institutional uses. The Riverfront Crossings District developed an industrial character starting in the early days of the city, reinforced by its proximity to the railroad yards and train depot. Today, retail, office, and service establishments, many locally owned, predominate on South Gilbert Street and Kirkwood Avenue; businesses cite high visibility, comparatively low rents, and on-site parking as positive attributes of the location.1 The building scale and pedestrian orientation along Kirkwood Avenue is similar to a traditional main street. The remainder of the area has a mix of industrial and intensive commercial uses, including a concentration of auto repair business south of Kirkwood Avenue, residential apartments, and public institutional uses. 1 Central District Plan, October 21, 2008.
5
analysis
site context
physical features
natural features
DRAFT riverfront crossings sub-area plan6
site context
University of Iowa
Downtown Iowa City/University of Iowa
10
m
i
n
.
w
a
l
k
5 m
i
n
.
w
a
l
k
Riverfront Crossings District Vicinity Map
1/4 Mile (5 minute walk)
1/2 Mile (10 minute walk)
Riverfront Crossing District Boundary
Riverfront Crossings Sub-Area Boundary
N
0’ 250’ 500’ 1000’
KIRKWOOD AVENUE
BENTON STREET
LAFAYETTE AVENUE
GILB
E
R
T
S
T
R
E
E
T
CA
P
I
T
O
L
S
T
R
E
E
T
CL
I
N
T
O
N
S
T
R
E
E
T
DU
B
U
Q
U
E
S
T
R
E
E
T
HIGHW
A
Y
6
HIGHLAND AVENUE
I
O
W
A
R
I
V
E
R
RAL
S
T
O
N
C
R
E
E
K
The Riverfront Crossings District is located just south of Downtown
Iowa City and southeast of the heart of the University of Iowa
Campus. It is bounded by Burlington Street on the north, U.S.
Highway 6 on the south, Riverside Drive on the west and South
Van Buren/Boyrum Streets on the east. The sub-area is located in
the southern portion of the larger district, bounded by the Iowa
Interstate Railroad on the north, U.S. Highway 6 on the south, the
Iowa River on the west and the CRANDIC Rail Line on the east.
vicinity map
7
1
2
2
3
3
44
1
2
3
4
5
Rock Island Train Depot
Substation
City Carton Recycling
Johnson County Administrative Offices
North Wastewater Treatment Facility
5
N
DRAFT riverfront crossings sub-area plan8
physical features
The study area straddles the floodplain on the east bank of the Iowa
River. The auto-oriented area contains low-rise structures and the
North Wastewater Treatment Plant. Its proximity to the Iowa River
and location along rail lines encouraged industrial and commercial
uses, with a limited number of retail and office uses lining Gilbert
Street. From a vehicular standpoint, the site is well connected.
U.S. Highway 6 and Benton Street/Kirkwood Avenue are primary
arterial streets that run east-west through the area. Gilbert Street is
the primary north-south arterial within the study area. The Benton
Street and the U.S. Highway 6 bridges over the Iowa River provide
direct access to the study area from neighborhoods located to the
west. To accommodate through-traffic on Benton Street/Kirkwood
Avenue, a full block “traffic circle” was developed. This modification,
which incorporated one-way streets, significantly altered the
traditional network of two-way streets. Over time, this framework
has led to real and perceived deficiencies in the area’s pedestrian
environment. Redevelopment of the study area should balance
the regional needs of commuters with the local desire to create a
pedestrian-friendly street network conducive to residential and
mixed-use development.
The major trail located in the study area is the Iowa River Corridor
Trail. This trail is 6 miles in length and provides access to major
points in Iowa City. The trail parallels the east bank of the Iowa
River, except where it swings to the east around the North
Wastewater Treatment Plant. The trail connects to the west side of
the Iowa River via the Benton Street bridge. Future trail extensions
will connect the Iowa River Corridor Trail with new development
within the study area.
Currently, the major bus routes in the study area run north/south
along Gilbert Street and connect to Capitol Street via the Kirkwood
Avenue/Clinton Street one-way pair. As redevelopment occurs and
traffic patterns change, the bus routes within the area will need
to be re-examined to ensure full coordination with the district’s
mobility objectives. Bus stops within the study area currently
consist of small signs with few public amenities. Future bus stops
should be designed with enhanced signage and route information
and provide amenities such as shelters, benches, and bicycle
parking.
Two rail lines also bisect the study area - the CRANDIC Railroad
which runs north/south through the district and the Iowa Interstate
Railroad which runs east/west through the district. Both rail lines
Riverfront Crossings District Existing Built Form
Existing Buildings
Parcels
Existing Waterways
Riverfront Crossings Sub-Area Boundary
Rock Island Train Station
KIRKWOOD AVENUE
BENTON AVENUE
LAFAYETTE AVENUE
HIGHLAND AVENUE
HIGHWAY 6
I
O
W
A
R
I
V
E
R
CAP
I
T
O
L
S
T
R
E
E
T
CLIN
T
O
N
S
T
R
E
E
T
DUB
U
Q
U
E
S
T
R
E
E
T
GILB
E
R
T
S
T
R
E
E
T
R
A
L
S
T
O
N
C
R
E
E
K
N
0’ 150’ 300’ 600’
Riverfront Crossings District Existing Transportation
Existing Buildings
Parcels
Key Roads
Existing Bus Route
Existing Trails
Existing Rail Lines
Existing Waterways
Riverfront Crossings Sub-Area Boundary
Iowa Interstate
R
a
i
l
r
o
a
d
C
R
A
N
D
I
C
R
a
i
l
L
i
n
e
KIRKWOOD AVENUE
BENTON AVENUE
LAFAYETTE AVENUE
HIGHLAND AVENUE
HIGHWAY 6
I
O
W
A
R
I
V
E
R
CAP
I
T
O
L
S
T
R
E
E
T
CLIN
T
O
N
S
T
R
E
E
T
DUB
U
Q
U
E
S
T
R
E
E
T
GILB
E
R
T
S
T
R
E
E
T
R
A
L
S
T
O
N
C
R
E
E
K
N
0’ 150’ 300’ 600’
existingbuilt form existingtransportation
are designated as future transit lines. Amtrak is examining the east/
west line to be used as a high-speed rail line connecting Iowa City
to Chicago. The potential location for the Iowa City Station is the
1898 Rock Island Station located on Wright Street, just outside the
study area on the north, but located in the middle of the Riverfront
Crossings District. In addition, the north/south line is being
considered for light rail service from Cedar Rapids, North Liberty
and Coralville to Downtown Iowa City and the University of Iowa.
9
Riverfront Crossings District Topography
Existing Buildings
Parcels
Topography
Existing Waterways
Riverfront Crossings Sub-Area Boundary
LOW
HIGH
KIRKWOOD AVENUE
BENTON AVENUE
LAFAYETTE AVENUE
HIGHLAND AVENUE
HIGHWAY 6
I
O
W
A
R
I
V
E
R
CAP
I
T
O
L
S
T
R
E
E
T
CLIN
T
O
N
S
T
R
E
E
T
DUB
U
Q
U
E
S
T
R
E
E
T
GILB
E
R
T
S
T
R
E
E
T
R
A
L
S
T
O
N
C
R
E
E
K
N
0’ 150’ 300’ 600’
existingtopography
In June of 2008, the Iowa River crested almost 10 feet above flood
stage, inundating a large portion of the study area, including the
North Wastewater Treatment Plant. Properties north of Highway 6
and west of Dubuque Street were also affected. The flood prompted
Iowa City to plan for the relocation of the Treatment Plan and
Recycling Center, which would free up land in the floodplain for
future use as green space. This green space will be used as an
amenity and catalyst for redevelopment of the area, in addition to
protecting the area against future flooding.
A large portion of the study area is located within the 100 year and
500 year floodplain. The Plan works to keep private development
outside of the 100 year floodplain, making that land available for
future green space. The Study Area has relatively little change in
topography, except in the northern portion, which gradually rises
to the railroad. Subtle topographical changes along the riverfront
helped drive design decisions relating to the park and open space
system.
natural features
Riverfront Crossings District Existing Floodplain
Existing Buildings
Parcels
100-Year Floodplain
500-Year Floodplain
Existing Waterways
Riverfront Crossings Sub-Area Boundary
KIRKWOOD AVENUE
BENTON AVENUE
LAFAYETTE AVENUE
HIGHLAND AVENUE
HIGHWAY 6
I
O
W
A
R
I
V
E
R
CAP
I
T
O
L
S
T
R
E
E
T
CLIN
T
O
N
S
T
R
E
E
T
DUB
U
Q
U
E
S
T
R
E
E
T
GILB
E
R
T
S
T
R
E
E
T
R
A
L
S
T
O
N
C
R
E
E
K
N
0’ 150’ 300’ 600’
existingfloodplain
Aerial photo of the June 2008 flooding
N
DRAFT riverfront crossings sub-area plan10
2 3 4
6 7
8 10 11
1
5
9
1. Existing Rock Island Train Station located on Wright
Street
2. View of the Iowa River from study area3. Existing CRANDIC Rail Line and adjacent Substation
looking west4. Existing water treatment facility building terminating
Clinton Street
5. View of an existing water treatment tank 6. Recently built Johnson County office building with
adjacent parking garage7. View looking north from the study area – the old
Capitol Building and Johnson County Courthouse
Building can be seen in the distance8. Ralston Creek9. Recently built mixed-use Telluride Building north of
the study area
10. Johnson County Courthouse Building located north of
the study area11. Existing City Carton Recycling facility site
11
sub-area plan
planning workshop
plan
DRAFT riverfront crossings sub-area plan12
planning workshop
A planning workshop, held from October 4-6, 2010, allowed City Staff and key stakeholders an
opportunity to discuss and refine initial design concepts. Over the course of three days, the design
team created a framework plan for the development of the sub-area and a concept for the riverfront
park. A major outcome of the workshop was the evaluation and agreed upon solution for the Sub-
Area’s proposed new street network. Discussions regarding the density of development were driven
by FAA height restrictions in the southern portion of the study area.
Based on traffic volumes, accessibility and views, it was determined that the Gilbert Street corridor
would be redeveloped as a “main street” with ground-floor commercial and on-street parking.
Residential buildings to the west of Gilbert Street were designed to overlook the enhanced Ralston
Creek corridor and proposed riverfront park. A potential site for a small box retail store, which could
provide local goods and services, was identified at the northeast corner of the intersection of Gilbert
Street and Highland Avenue. A new Capitol Street/Kirkwood Avenue connector street was identified
and creates a new block for higher density residential with limited ground-floor commercial. Placed
outside of the FAA height restrictions, these potential tower sites take advantage of the riverfront
park and view of the Iowa River corridor. The northwest corner of the Benton Street/Clinton Street
intersection was reserved for the potential future Johnson County Ambulance Center.
A concept plan for the riverfront park, which would replace the existing wastewater treatment plant,
was created. This plan utilized existing topography and the adjacent street network to organize
space and site potential amenities. Development of the park will also displace the Iowa City Fire
Department Training Center, which the City hopes to relocate to a more suitable alternate location in
the district. A new trail system is designed to run along Ralston Creek and the Iowa River, connecting
to existing trails and providing easy access to the site. Active spaces include community gardens, an
amphitheatre, and parking areas. The southern portion of the park was designed with a large pond
and wetland to be used as a flood mitigation device and amenity for the park.
1 2
13
1. Photos of the workshop and interactive process. 2. The refined development concept showing building layout, location of parking and new street network. The riverfront park is designed with a variety of
multi-functional green spaces interconnected by trail and pedestrian pathways.3. An initial look at a Gilbert Street ‘road diet’ which employs on-street parking and reduces the street to three lanes with a center turn lane. It was later
decided that high travel volumes would not make this section applicable. Buildings would front onto the street with parking in the center of the block and
residential units overlooking Ralston Creek. 4. Evaluations of one-way, two-way and round-a-bout concepts for the Benton Street/Kirkwood Avenue connector street.
5. Graphics created during the workshop that examined potential configurations for parking and buildings at a range of densities.4
5
3
DRAFT riverfront crossings sub-area plan14
plan
The Riverfront Crossings District Sub-Area Plan was driven by six key project goals that were based on city, stakeholder, and community
visions for the future of the area.
•Develop a new mixed-use, pedestrian-oriented district
• Create a mix of housing, office and retail uses within the district• Develop a new urban fabric that is pedestrian-friendly
•Create a resilient riverfront park system
• Create parks for both the local community and the city that balance active and natural open spaces• Use flood mitigation measures to protect against future flooding
•Enhance Ralston Creek to become a community asset
• Priority should be given to protecting Ralston Creek and restoring it as a natural waterway
•Develop a multi-modal transportation network
• Reduce the dependence on the automobile by providing access to a variety of transportation options
•Create a network of green streets in the district
• Activate and improve streetscapes by providing enhanced pedestrian amenities• Landscaping and street trees will be essential for providing ecological benefit, pedestrian comfort, and aesthetic interest along the
sidewalk • Revert one-way streets back to two-way to create a pedestrian- and driver-friendly street grid network
•Promote sustainable design practices within the district
• Encourage a low impact development (LID) approach to design and development• Create a system of stormwater best management practices (BMPs) to control and cleanse runoff throughout the district
I
O
W
A
R
I
V
E
R
R
A
L
S
T
O
N
C
R
E
E
K
Kirkwood Ave.
Highland Ave.
Benton St.
Lafayette St.
Gi
l
b
e
r
t
S
t
.
D
u
b
u
q
u
e
S
t
.
C
l
i
n
t
o
n
S
t
.
C
a
p
i
t
o
l
S
t
.
Highw
a
y
6
15
I
O
W
A
R
I
V
E
R
R
A
L
S
T
O
N
C
R
E
E
K
Kirkwood Ave.
Highland Ave.
Benton St.
Lafayette St.
Gi
l
b
e
r
t
S
t
.
D
u
b
u
q
u
e
S
t
.
C
l
i
n
t
o
n
S
t
.
C
a
p
i
t
o
l
S
t
.
Highw
a
y
6
18
17
16
1317
14
157
7
7
12
11
8 9
10
4
4
4
6
5
2
2
1
13
1 Rock Island Train Depot/potential high-speed rail stop station
Existing substations
Potential site for relocation of the Iowa City Fire Training Center
Residential towers
Johnson County Ambulance Center
New Capitol St./Kirkwood Ave. connector street
River overlooks
Community gardens
Existing structure
Playground
Amphitheatre
Access ramp for water recreation
Potential light rail stop
Ralston Creek bank restoration
Constructed wetland and habitat restoration
Gilbert Street corridor redevelopment
Residential courtyard
Small box retail
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
N
0’150’300’600’
3
18
DRAFT riverfront crossings sub-area plan16
Rendering showing proposed development and riverfront park system along the Iowa River. The new park will provide a variety of spaces for multiple uses throughout the year. The green space will be a catalyst for redevelopment of the area.
17
framework elements
mobility
green space
DRAFT riverfront crossings sub-area plan18
****
**
mobility
The Riverfront Crossings Sub-Area is designed to encourage sustainable modes of transportation.
Providing an interconnected system of pedestrian, bicycle, transit and vehicular movements will give
residents and visitors multiple options for travel. Expanding on and improving the existing networks
will be important to create the pedestrian-friendly environment envisioned for the District. Investment
should focus on the provision of public amenities that are consistent throughout the area to enhance
the image and identity of the mobility network within the Riverfront Crossings District.
pedestrian
bicycle
transit
streets
base built form
19
pedestrian Enhancements to the public realm will
need to be made to create the walkable, pedestrian-oriented
environment that is envisioned for the area. Currently, sidewalk
connectivity is limited, which creates an uninviting place for
pedestrians. The design for the public realm, including streets and
the placement of buildings, will greatly affect the quality of place
for Riverfront Crossings. Pedestrian comfort and safety should be
placed at a premium during design phases. The circulation pattern
should continue the gridded network of streets already in place,
while connecting to the larger trail network along the Iowa River. To
connect residents and visitors along the Gilbert Street corridor to
the riverfront park, east/west connections, with pedestrian bridges
across Ralston Creek, should be developed. Consideration should
be taken to provide amenities for pedestrians, including street
furniture and landscape amenities.
bicycle Bicycle facilities were included in the design of the
Sub-Area to help promote a variety of mobility options. Currently,
the bicycle network includes on-street facilities designated as
‘sharrows’ (shared bike and automobile lanes) and the off-street
Iowa River Corridor Trail that runs along the Iowa River and passes
through the southwestern corner of the study area. Clinton Street
and Gilbert Street are designed as sharrows due to the connection
to Downtown Iowa City. Off-street facilities should include an
expanded trail network that connects the Iowa River Corridor Trail
to the north and south and includes connections along Ralston
Creek and Capitol Street. Providing both on-street and off-street
bicycle facilities will provide the Riverfront Crossings district
multiple options for bike riding. Bike parking, lockers, and other
amenities should also be provided in the District.
transit The Riverfront Crossings District will be served by
future potential high-speed and light rail service. Along with the
proposed high-speed rail station at the former Rock Island Station,
two light rail stations are proposed to help create a transit-oriented
neighborhood. The southern stop, along 1st Street, will be the
access point for the Gilbert Street corridor and the riverfront park.
The north stop will pair with the high-speed rail station to create an
intermodal center at the north end of the Sub-Area.
Bus service will be expanded within the District to provide more
local access for residents and visitors of the neighborhood and
park. The existing bus line will be realigned to continue through the
new Capitol Street/Kirkwood Avenue connector street. Bus stops
are proposed at key intersections, most notably at Gilbert Street
and 1st Street. This stop will help to integrate bus and light-rail
riders. Transit stops should be taken into account when designing
the roadway network within the Sub-Area. Providing public
amenities at the stops will improve ridership and enhance the
image of the Riverfront Crossings District.
KIRKWOOD AVENUE
BENTON AVENUE
HIGHWA
Y
6
I
O
W
A
R
I
V
E
R
CA
P
I
T
O
L
S
T
R
E
E
T
CL
I
N
T
O
N
S
T
R
E
E
T
GIL
B
E
R
T
S
T
R
E
E
T
KIRKWOOD AVENUE
BENTON AVENUE
HIGHWA
Y
6
I
O
W
A
R
I
V
E
R
CA
P
I
T
O
L
S
T
R
E
E
T
CL
I
N
T
O
N
S
T
R
E
E
T
GIL
B
E
R
T
S
T
R
E
E
T
**
*
**
*
KIRKWOOD AVENUE
BENTON AVENUE
HIGHWA
Y
6
I
O
W
A
R
I
V
E
R
CA
P
I
T
O
L
S
T
R
E
E
T
CL
I
N
T
O
N
S
T
R
E
E
T
GIL
B
E
R
T
S
T
R
E
E
T
Future Bus Routes Proposed Bus Routes Bus Stops
Potential Light Rail / Stop (Future) Commuter Rail / Stop (Future)
Existing Trail Network Proposed Trail Network
Sharrows
Bus Routes Proposed Bus Routes Bus Stops
Potential Light Rail / Stop (Future) Commuter Rail / Stop (Future)
Pedestrian Network * Bus Routes Proposed Bus Routes Bus Stops
Potential Light Rail / Stop (Future) High Speed Rail / Stop (Future)
DRAFT riverfront crossings sub-area plan20
Capitol/Kirkwood Connector
P P
128’ Proposed Right-of-Way
Median/Turn Lane
Travel Lane
14'
12'SidewalkSidewalk Landscape/Furnishings
Median
8’10’8'7'
Slip Lane
12'
Parking
8'Landscape/Furnishings
7’
PrivateSetback
6-10’
6’ min.
Travel Lane
12'Median
10'
Slip Lane
12'
Parking
8'
Upper LevelStepback
Capitol/Kirkwood Connector (A-A’)
streets The current one-way configuration of the Benton Street/Kirkwood Avenue connector will be returned to a two-way street network. To ensure that the arterial nature of the current
configuration is continued, a new connector street from Capitol Street to Kirkwood Avenue will be developed. This connector street will produce a new development block overlooking the proposed riverfront
park.
Taking into account existing and future development and traffic volume, Gilbert Street will need to be redeveloped as a 5-lane roadway with a center turn-lane and landscaped median. This will require an
increase from the current 66’ right-of-way (ROW) to a 114’ ROW. On-street parking will be provided on the northern portion of the Gilbert Street corridor to help encourage ground-floor commercial uses.
On-street parking will also help to create a buffer between traffic flow and pedestrians walking on the sidewalk, providing enhanced safety. Commercial uses are designated on the side streets off of Gilbert
Street. These side streets will help provide additional on-street parking to help enliven the sidewalk and allow customers easy access from the street. Per the traffic analysis, the Gilbert Street/U.S. Highway 6
intersection will need to be increased to seven lanes to allow for southbound dual left-turn lanes. Outside lanes will be designated as shared bicycle and motorist lanes, or ‘sharrows.’
Compared to the auto-only character of the current streets, with few, if any pedestrian and bicycle amenities, the proposed street network in the Sub-Area will create urban street sections that provide safe and
convenient movement for pedestrians, bicycles, transit, and automobiles. Amenities such as outdoor seating, street trees, lighting, and bike racks will help build vibrant street life.
The illustrative street sections conceptually identify proposed rights-of-way and recommended functions. Additional traffic study will be needed to finalize roadway design recommendations, as achieving the
intended street character will be important to balance the transportation goals for pedestrians, bicycles, transit, and automobiles.
mobility
KIRKWOOD AVENUE
BENTON AVENUE
HIGHW
A
Y
6
I
O
W
A
R
I
V
E
R
CA
P
I
T
O
L
S
T
R
E
E
T
CL
I
N
T
O
N
S
T
R
E
E
T
GIL
B
E
R
T
S
T
R
E
E
T
Bus Routes Proposed Bus Routes Bus Stops
Potential Light Rail / Stop (Future) Commuter Rail / Stop (Future)
Street Network/Parking
21
Gilbert Street
P P
8'8'Median
114’ Proposed Right-of-Way
SharrowParking ParkingTravel Lane Travel Lane Sharrow
14'12'12'14'SidewalkSidewalk Landscape/Furnishings Landscape/Furnishings
8’7’16'8'7'
60’ Existing Right-of-Way
1st Street
18'18'
90’ Proposed Right-of-Way
Parking ParkingTravel Lane Travel Lane
12'12'SidewalkSidewalk Landscape/Furnishings Landscape/Furnishings
8’7’8'7'P P
60’ Existing Right-of-Way
Clinton Street
18'18'
100’ Existing Right-of-Way
Parking ParkingSharrowSharrow
15'15'SidewalkSidewalk Landscape/Furnishings Landscape/Furnishings
8’8’9’8'9'
ExistingSetback Existing Parking Garage
P P
PrivateSetback
6-10’
Gilbert Street section (C-C’)1st Street section (B-B’)
Clinton Street section (D-D’)
A A’
C C’
B
B’
D D’
DRAFT riverfront crossings sub-area plan22
The public parks and open space plan consists of different
types of green space that will respond to both community and
environmental needs. The riverfront park will contain both passive
and active green space. The plan illustrates a spatial layout that
provides opportunities for a variety of park amenities, such as
public plazas, outdoor gathering spaces, trails, community gardens,
river overlooks, access ramps to the Iowa River, and areas used for
stormwater management. Passive recreation areas with sidewalks,
trails, informal green space, and natural areas will be located in
flood-prone areas along the Iowa River and Ralston Creek. The
large green space at the center of the park is an appropriate
location for more active uses, such as a playground, amphitheater,
and community gardens. A parking area for visitors is located in this
central, higher activity area. The plan illustrates how the east-west
connections to the park from the Gilbert Street corridor extend
all the way to the river providing easy access for boating and to
overlooks for bird watching, fishing and views up and down the
Iowa River. Smaller residential courtyards will be located along
these east/west connections and provide green “fingers” into the
Gilbert Street corridor. .
green space
Riverfront Crossings District Public Realm
Development Blocks
Manicured Landscape
Naturalized Landscape
Trees
Existing Waterways
Riverfront Crossings Sub-Area Boundary
KIRKWOOD AVENUE
BENTON AVENUE
LAFAYETTE AVENUE
HIGHLAND AVENUE
HIGHWA
Y
6
I
O
W
A
R
I
V
E
R
CA
P
I
T
O
L
S
T
R
E
E
T
CL
I
N
T
O
N
S
T
R
E
E
T
DU
B
U
Q
U
E
S
T
R
E
E
T
GIL
B
E
R
T
S
T
R
E
E
T
R
A
L
S
T
O
N
C
R
E
E
K
N
0’ 150’ 300’ 600’
public realm
23
1. Green space along the river provides places for recreation
and relaxation in Boston, MA2. A riverfront trail located along the Missouri River in
Omaha, NE 3. A large green space in Council Bluffs, IA is used as an
outdoor amphitheatre4. Community gardens in Omaha, NE provide places for
interaction among residents and a place for urban
agriculture5. Overlook pier in Portland, OR allows visitors to take in
expansive views of the river corridor6. Residential units are designed to overlook the new
riverfront park and trail system.
4
5
1 2 3
6
DRAFT riverfront crossings sub-area plan24
E
E’
1st Street - Residential Courtyard
40'
15’
70’ Proposed Right-of-Way
Central Green with Stormwater Element
Sidewalk PrivateSetbackSidewalk
6-10’15'
PrivateSetback
6-10’
1. Residential units along 1st Street are designed to
front onto small courtyards offering recreational and
stormwater functions. The large sidewalks provide access
and views into the riverfront park across Ralston Creek.
2. Residential building fronting onto greenspace in
Portland, OR3. A pedestrian-only courtyard in Portland, OR
4. Locator diagram
1
2 3
1st Street Residential Courtyard (E-E’)
4
25
stormwater bmps
DRAFT riverfront crossings sub-area plan26
Riverfront Crossings District
Water Resources
Recommended Stormwater BMP Locations Constructed Wetlands Proposed Buildings*
Existing Waterways
Riverfront Crossings Sub-Area Boundary * Green Roof Potential
KIRKWOOD AVENUE
BENTON AVENUE
LAFAYETTE AVENUE
HIGHLAND AVENUE
HIGHWA
Y
6
I
O
W
A
R
I
V
E
R
CA
P
I
T
O
L
S
T
R
E
E
T
CL
I
N
T
O
N
S
T
R
E
E
T
DU
B
U
Q
U
E
S
T
R
E
E
T
GIL
B
E
R
T
S
T
R
E
E
T
R
A
L
S
T
O
N
C
R
E
E
K
N
0’ 150’ 300’ 600’
water resources
stormwater bmps
The Riverfront Crossings District should be designed to minimize
the impact of stormwater runoff on the environment. A key goal of
the Sub-Area Plan is to encourage the development of stormwater
facilities throughout the area. The riverfront park has the potential
to be designed to address water quality and quantity issues at a
regional scale, as well as flood control during larger storm events.
Ralston Creek has the opportunity to be designed to both stabilize
the creek bank and create a restored riparian corridor alongside
the creek. This area would include pockets of wetlands and native
vegetation that would provide wildlife habitat and ecological
benefit. A larger constructed wetland is designated for the southern
portion of the riverfront park. This wetland would be designed to
retain, infiltrate and treat stormwater runoff. Throughout the Sub-
Area there are opportunities to spread, slow down, and/or treat
stormwater runoff before it enters Ralston Creek or the Iowa River.
These facilities should be designed to work together toward an
integrated stormwater management approach. Public outreach and
education should be part of this approach. While the conceptual
plan identifies potential areas where runoff mitigation is possible,
further study will be necessary to provide technical expertise and
to identify the appropriate locations for stormwater management
facilities. On-going inspection and maintenance appropriate
to each facility will be important to assure proper long-term
functioning.
27
Mixed Use
Building
Mixed Use
Building
Gilbert Street Access and Surface Parking Residential
Building
Pedestrian
Zone
Ralston Creek
Habitat
Pervious Pavement
Pervious Concrete
Pervious Asphalt
Pervious Paver System Stormwater Planter
Infiltration Planter
Flow-Through Planter Rainwater Harvesting
Rain Barrel
Cistern System Landscape Parking Median
Vegetated Filter
Rain Garden Swale
Vegetated Swale
Grassy Swale
Sand Filter
Green Roof
Intensive Planting
Extensive Planting Creek
Channel Stabilization
Constructed Wetlands
stormwater transect
DRAFT riverfront crossings sub-area plan28
stormwater planter Landscape planters placed along the street provide opportunity for retention,
infiltration, and/or treatment of water during storm events. Instead of transporting polluted water downstream, these facilities are de-
signed with a wide variety of vegetation to slow down and treat stormwater. Curb-cuts will divert storm flows into the planters. Street
site distances at intersections should be maintained by selecting low groundcover type plantings. This type of BMP helps to provide an
aesthetic and ecological function to the street.
pervious pavement Combined with other stormwater BMPs, pervious pavement helps to slow down
and infiltrate polluted water before leaving a site. Pervious pavement can be placed in parking areas but should be avoided in high
traffic areas. There are a variety of pervious pavement types including modular porous pavement systems, pervious concrete, porous
asphalt, and reinforced grass pavers. All of these systems allow water to percolate through the pavement into a sub-layer of aggregate
before infiltrating into the soil. Pervious pavements also help to filter sediment from runoff and therefore should be placed at the
beginning of a BMP treatment network (here with a vegetated infiltration basin).
29
rainwater harvesting This BMP involves the collection, storage, and reuse of stormwater runoff from
building roofs. Rainwater harvesting reduces runoff volume and peak flows and can provide full water cycle benefit to communities.
Depending on rooftop material and harvesting system used, collected rainwater may be used for landscape irrigation, drinking water,
and greywater uses, such as flushing toilets. Some of these may require treatment before use. Rainwater harvesting systems may be as
inexpensive and simple as a rain barrel connected to a downspout to more complex systems such as an underground catchment tank.
landscape parking median Rain gardens are designed to filter, infiltrate, and treat
stormwater runoff. Stormwater is treated as it passes through the plant and soil community. Their relatively small size allows them
to be placed in many different locations, including parking medians and near buildings. Typically planted depressions, rain gardens
should be designed in areas with well-drained soils to allow for infiltration If well-drained soils are not available, amending the soil
with a more permeable mix is advised. A plant palette that can tolerate wet and dry cycles is necessary.
DRAFT riverfront crossings sub-area plan30
green roof In urban areas, building roofs account for a large portion of impervious surface. These roofs can be planted
with vegetation to help treat and retain stormwater. Green roofs require structural improvements to support soils, vegetation, and
loads associated with rainfall and snowfall. Benefits include providing habitat for plants, animals, and insects, reducing the heat island
effect, and providing a development tool to create green space in otherwise under-utilized space. Vegetation should ideally be native
species that are drought tolerant.
swale Swales are designed to help collect, filter, and/or infiltrate runoff and convey it to an adjacent stormwater management
facility. Swales can be planted with vegetation or designed in more poorly-drained soils with an aggregate trench to allow infiltration.
If planted, native vegetation should be used to minimize maintenance and provide ecological benefit. Swales should be designed
between buildings, parking areas and alongside roadways to slow down peak flows and to move water to an acceptable location.
31
creek Ralston Creek is an important natural drainageway in Iowa City. Years of urbanization and stormwater runoff have
degraded the creek and significantly eroded its banks. An important aspect of the new riverfront park should be the implementation
of bank stabilization and restoration of Ralston Creek. Rather than structural solutions for the creek, “soft” methods should be used,
including channel shaping and restored riparian corridor vegetation. This vegetative buffer will help to filter and treat runoff prior to
entering the creek, enhancing the water quality and function of the stream, while also providing wildlife habitat. This will help Ralston
Creek become a multi-functional community asset for Iowa City. Ralston Creek Restoration
20' min.10' min.
Creek Bank Greenway PrivateSetbackZone 1
6-10’30'
Zone 2
20’10'
Trail30'
Creek
Zone 3
25’
Trail
10’
PrivateSidewalk
6’
constructed wetlands Wetlands provide a full range of ecological services for polluted runoff,
including retention, infiltration, and treatment as well as educational and aesthetic benefits for surrounding communities. Constructed
wetlands are man-made but are designed to replicate the natural system. They enhance water quality and provide flood storage.
Depending on the size of catchment, constructed wetlands are typically large in scale to provide enough area for water storage,
vegetative cover, and wildlife habitat. Vegetation should consist of a variety of native species well-suited for wet soil conditions.
DRAFT riverfront crossings sub-area plan32
1. A large constructed wetland is proposed on the southern end of the new riverfront park. A
boardwalk provides close encounters with the diverse vegetation and habitat. This wetland will
provide flood storage and habitat restoration for the Riverfront Crossings District. Residential
towers are seen in the background overlooking the park and river.
2. A pedestrian bridge across the headwaters of the Mississippi River in Itaska State Park, MN
provides access and views of creek habitat
3. This boardwalk in Woodinville, WA is sensitive to the adjacent wetland habitat
4. Construction photo of ‘soft’ bank stabilization methods at Indian Run Creek near Concord, NC
1
2
3
4
33
design guidelines
land use
heights
frontages and setbacks
parking and access
special requirements
DRAFT riverfront crossings sub-area plan34
The Riverfront Crossings Sub-Area will be developed as a mixed-use
neighborhood that provides new opportunities for people to live
within walking distance of jobs, shopping, recreation, and cultural
amenities in the downtown area. Gilbert Street will be designed
as a main street with frontages and ground floor building spaces
attractive to retailers, restaurants, and other desired commercial
uses. The high traffic volumes at the intersection of U.S. Highway 6
and Gilbert Street will be important for retail to function properly.
The high volume and visibility of this intersection may support a
small box retail store, which would provide goods and services to
the adjacent neighborhoods.
A considerable amount of residential is encouraged to maximize
the economic potential of the area, create the threshold of
consumer demand necessary to attract neighborhood-serving
businesses, and to realize the desired return on investment in
additional transit service, park amenities, and street infrastructure.
A mix of residential unit types is proposed to take advantage of
Ralston Creek and the riverfront park, with townhouses fronting on
courtyards west of Gilbert Street and denser residential typologies
fronting onto the park. The north development blocks will be
primarily residential, with key frontages designed to accommodate
ground-floor commercial intermixed. The northern most block
should be mixed-use in nature to take advantage of the adjacent
potential high-speed rail station and light rail stop. The variety,
size, and design of the residential units should further the goal of
creating a neighborhood with a stable population of long-term
residents of all incomes and ages, rather than focusing on the
market for university student housing.
Recent market analyses indicate that there is also a need for office
and hotel space in the downtown area. Offices can easily be mixed
within buildings, both on the upper and lower floors along Gilbert
Street and in the blocks overlooking the new park. Hotels should
be designed to fit into the pedestrian-oriented, urban context of
the area.
Auto-oriented uses, such as gas stations and drive-through
facilities are generally disruptive along a pedestrian-oriented
street frontage. However, there may be limited locations that are
acceptable for such uses and facilities. See Appendix A for a more
detailed description for how to incorporate these uses into the
district.
Riverfront Crossings District
Land Use
Residential
Civic
Mixed Use
Commercial
Parking Structure
Potential Rail Stations
Existing Waterways
Riverfront Crossings Sub-Area Boundary
KIRKWOOD AVENUE
BENTON AVENUE
LAFAYETTE AVENUE
HIGHLAND AVENUE
HIGHWAY
6
I
O
W
A
R
I
V
E
R
CA
P
I
T
O
L
S
T
R
E
E
T
CL
I
N
T
O
N
S
T
R
E
E
T
DU
B
U
Q
U
E
S
T
R
E
E
T
GIL
B
E
R
T
S
T
R
E
E
T
R
A
L
S
T
O
N
C
R
E
E
K
N
0’ 150’ 300’ 600’
land use
35
1. Residential units with balconies overlooking green space
in Omaha, NE2. Ground floor commercial with large windows in Boise, ID
provide areas for merchandise display that gives visual
interest and activates the sidewalk
3. Two and three level townhouses line the street in Belmar,
CO4. This mixed-use building in Omaha, NE has offices and
residential units above ground floor commercial5. Redevelopment along the Gilbert Street corridor should
be mixed-use and provide street level activity. A small box
retail store is placed at U.S. Highway 6 and Gilbert Street
intersection to take advantage of the highly traveled
roadways and views to the site. Residential units are
proposed on the east/west courtyards to the riverfront
park and along Ralston Creek.
6. In Southlake, TX, this commercial box store is designed
with architectural detail to create a more pedestrian
friendly environment
2 3 4
6
1
5
DRAFT riverfront crossings sub-area plan36
The building heights of the Sub-Area are based on the desired
urban form of the district, market analysis of the residential and
commercial demand, and FAA airport height restrictions. The
southern portion of the Sub-Area along Gilbert Street is located
within the flight path and transition zone of the Iowa City Municipal
Airport. These areas are regulated by the FAA and provide vertical
height limits. In response, building heights will transition from
1-3 levels on the southern end to 4-6 levels on the northern end
of the Gilbert Street blocks. Outside of the transition zone, in the
northern blocks, residential towers of 7+ levels (on top of lower
rise residential pedestal buildings) are proposed. These residential
towers will take full advantage of the riverfront park and views
of the Iowa River. Minimum and maximum building heights are
proposed to create an acceptable urban form within the Sub-Area.
Developers will need to work with the City to ensure that proposed
building heights meet FAA airport height regulations.
Riverfront Crossings District
Heights
1 Level
2-3 Levels
4-6 Levels
7-13 Levels*
Stepback requirement
Existing Waterways
Riverfront Crossings Sub-Area Boundary
*max height contingent on ight zone
7:1 slope
TRANSITIO
N
Z
O
N
E
1
5
0
’
H
E
I
G
H
T
L
I
M
I
T
FLIGHT P
A
T
H
KIRKWOOD AVENUE
BENTON AVENUE
LAFAYETTE AVENUE
HIGHLAND AVENUE
HIGHWAY
6
I
O
W
A
R
I
V
E
R
CA
P
I
T
O
L
S
T
R
E
E
T
CL
I
N
T
O
N
S
T
R
E
E
T
DU
B
U
Q
U
E
S
T
R
E
E
T
GIL
B
E
R
T
S
T
R
E
E
T
R
A
L
S
T
O
N
C
R
E
E
K
N
0’ 150’ 300’ 600’
heights
TRANSITIO
N
Z
O
N
E
TRANSITION ZONE
FLIGHT PATH
37
1 2 3
4 5 6 7
8 9 10
1. A two level mixed-use building on the corner with
ground floor commercial located in Longmont, CO2. A setback above 4 levels is located on this mixed-use
building in Portland, OR
3. Three level townhouses located in Denver, CO4. Residential units above ground floor commercial help
frame a street in Denver, CO5. A three level mixed-use building with on-street parking
located in Phoenix, AZ
6. Smaller three level townhouse units are designed at
the base of a larger residential tower in Portland, OR
7. A three level building with ground floor commercial
and outdoor seating in Omaha, NE8. Three and four level residential units front onto a
large parkway in St. Paul, MN9. A small box retail store with 2 levels on the corner in
Mashpee, MA10. A residential tower with adjacent three level
townhouses in Omaha, NE
DRAFT riverfront crossings sub-area plan38
Guidelines for frontages and setbacks help to ensure the proper
engagement of buildings within the public realm. This will help
to ensure that the interface between the building and sidewalk is
detailed appropriately.
Frontages that are assigned “active” will be built to the property
line, except to accommodate desired articulation of building
façades, recessed doorways, outdoor plaza or cafe spaces, public
art features, or other pedestrian amenities. Building setbacks
necessary to achieve such desired articulation and street-side
amenities should not exceed 12 feet. This build-to-line will ensure
that ground floor commercial spaces will be properly designed
to activate the street. Shopfronts should be designed with a high
percentage of glazing and prominent pedestrian entrances at or
near grade. Storefront windows should be clear glass to allow
views into building interiors. Awnings or canopies are encouraged
and should be allowed to encroach into the public ROW a minimum
distance to provide pedestrians with shade and shelter from
inclement weather, to protect window displays from sun damage,
and prevent excessive glare that may obscure views to or from shop
interiors.
Residential units will be designed with a 6–16 foot setback. This
setback will allow for landscape and architectural treatments to
help give privacy to the ground floor unit. Stoop, porch, and terrace
encroachments will be allowed within the setback zone to allow
for an interface with the sidewalk. Care should be taken when
regulating minimum stoop, porch, or terrace depth to ensure that
usable spaces are created.
Along Gilbert Street, all frontages should be built with shopfront
features to encourage commercial uses on the ground floor.
However, as illustrated on the map, the mid-block locations may
also be suitable for live-work units where a 6-10 foot residential
setback would allow for additional landscaping, outdoor seating,
and/or other amenities attractive to both residents and businesses
located on the ground level. Stoop and dooryard frontages may be
appropriate in mid-block locations toward the southern end of the
Gilbert Street corridor where on-street parking is not available.
Riverfront Crossings District
Frontages and Setbacks
Residential - Creek 12-16’ Setback
Residential 6-10’ Setback
Commercial / Active 0’ Setback
Existing Waterways
Riverfront Crossings Sub-Area Boundary
KIRKWOOD AVENUE
BENTON AVENUE
LAFAYETTE AVENUE
HIGHLAND AVENUE
HIGHWAY
6
I
O
W
A
R
I
V
E
R
CA
P
I
T
O
L
S
T
R
E
E
T
CL
I
N
T
O
N
S
T
R
E
E
T
DU
B
U
Q
U
E
S
T
R
E
E
T
GIL
B
E
R
T
S
T
R
E
E
T
R
A
L
S
T
O
N
C
R
E
E
K
N
0’ 150’ 300’ 600’
frontages and setbacks
39
1 2 3
4 5 6 7
8 9 10
1. This canopy in Omaha, NE protects the entrance to the
ground-floor commercial use.
2. Formal, fenced-in outdoor seating helps to create a
vibrant sidewalk in Washington D.C.3. Retail storefronts and canopies front directly onto the
sidewalk to engage passersby in Winter Park, FL.4. Outdoor seating along this sidewalk provides interaction
with pedestrians in St. Louis, MO
5. A small residential setback in Portland, OR allows for
privacy via a raised stoop and balcony frontage.
6. Townhouses setback from the sidewalk allow for a
stoop frontage in Atlanta, GA7. In Seattle, WA residential units are setback to allow
for a privacy wall and small stoop frontage along the
sidewalk.
8. Larger setbacks for these residential units allow for
stoop frontage and landscaping in Southlake, TX9. Ground floor residential units share stoop entrances
and front onto a green space in Addison, TX10. Storefronts with canopies protect window shoppers in
Seattle, WA
DRAFT riverfront crossings sub-area plan40
The type of parking and how it is accessed should be addressed
for proper development of the Sub-Area. Entries to parking
areas should be limited from the street to ensure a comfortable,
pedestrian-oriented environment. The more entries, the more
unsafe and inconvenient the area becomes for pedestrians. With the
exception of the small commercial box store, parking should always
be located to the rear of buildings and accessed through alleys. The
access to, and location of, utilities, loading docks, and dumpsters
should be located to the rear of buildings so as not to detract from
the pedestrian experience. On-street parking should be provided
whenever possible to activate the street and provide a buffer for
pedestrians. The intent of the Sub-Area Plan is to provide enough
parking within each development block to accommodate its
adjoining uses. The number of parking spaces will be determined
by the density of development, with higher density blocks requiring
structured parking solutions.
Riverfront Crossings District
Parking and Access
On-Street Parking
Surface Parking
Parking Structures
Access
Existing Waterways
Riverfront Crossings Sub-Area Boundary
KIRKWOOD AVENUE
BENTON AVENUE
LAFAYETTE AVENUE
HIGHLAND AVENUE
HIGHWAY
6
I
O
W
A
R
I
V
E
R
CA
P
I
T
O
L
S
T
R
E
E
T
CL
I
N
T
O
N
S
T
R
E
E
T
DU
B
U
Q
U
E
S
T
R
E
E
T
GIL
B
E
R
T
S
T
R
E
E
T
R
A
L
S
T
O
N
C
R
E
E
K
N
0’ 150’ 300’ 600’
parking and access
41
1. Parallel on-street parking is delineated by permeable
pavers in Washington D.C.2. A small landscaped courtyard provides access to a
parking garage in Legacy, TX
3. In Madison, WI, the garage entry is accessed by an alley
located to the rear of residential buildings4. Parking for these townhouses in Kansas City, MO is
located to the rear of the buildings in attached garages
which are accessed via an alley
5. Mixed-use buildings in Falcon Heights, MN surround the
parking lot to conceal it from the street
1 2 3
4 5 6
7 8 9 10
6. Surface parking lot accessed through a small break in
the street wall in Dubuque, IA7. Landscaping and architectural detailing help to hide
this parking garage in Winter Haven, FL so that it does
not take away from the pedestrian experience along the
sidewalk
8. Parallel on-street parking helps to provide safety
for pedestrians and direct access to neighborhood
businesses in Portland, OR9. Angled parking in Sarasota, FL provides more on-street
spaces than parallel parking
10. Surface parking lots should be designed with extensive
landscaping, as shown in Southlake, TX
DRAFT riverfront crossings sub-area plan42
The Sub-Area Plan is designed to create a well connected
environment. Axial relationships help to reinforce the public realm
network and to provide areas of civic importance. Vertical elements
such as buildings, statues, fountains, or other public art should be
designed in these areas. Individual buildings should be designed
to respond to key functional and aesthetic cues. Important corners
should receive special architectural features, such as façade
enhancements, turrets, and/or entrance embellishments. All street
facing buildings should be required to have a minimum level of
architectural treatment, but higher design standards should be
placed on buildings fronting the park and along key streets and
corners.
Riverfront Crossings District
Special Requirements
Enhanced Facades
Axial Views
Terminated Vistas
Existing Waterways
Riverfront Crossings Sub-Area Boundary
KIRKWOOD AVENUE
BENTON AVENUE
LAFAYETTE AVENUE
HIGHLAND AVENUE
HIGHWAY
6
I
O
W
A
R
I
V
E
R
CA
P
I
T
O
L
S
T
R
E
E
T
CL
I
N
T
O
N
S
T
R
E
E
T
DU
B
U
Q
U
E
S
T
R
E
E
T
GIL
B
E
R
T
S
T
R
E
E
T
R
A
L
S
T
O
N
C
R
E
E
K
N
0’ 150’ 300’ 600’
special requirements
43
1. An iconic sculpture is strategically placed within
greenspace in Kansas City, MO
2. Special treatment is given to this mixed-use corner in
Austin, TX3. In Frisco, TX, the articulation of building mass helps to
give definition and visual interest to pedestrians
4. This fountain in Celebration, FL terminates the main
retail street5. Different materials and an articulated facade
emphasize this building in Portland, OR
1 2 3 4
5 6 7
8 9 10
6. This corner is defined by taller building height and
variation of window size in Belmar, CO7. Sidewalk vegetation frames the view corridor to the
Gateway Arch in St. Louis, MO8. This allée of trees help define the sidewalk and provide
shaded areas of seating in this park in Celebration, FL9. This parking garage in Cheyenne, WY uses façade
enhancements to replicate neighboring buildings and
define the public realm10. A corner retail store in Southlake, TX terminates a
main view and articulates the corner with enhanced
architecture.
DRAFT riverfront crossings sub-area plan44
45
block analysis
development block diagrams
DRAFT riverfront crossings sub-area plan46
development block diagrams
The Riverfront Crossings Sub-Area contains nine development
blocks. Each of these blocks will contribute to the formation of a
new mixed-use, pedestrian friendly neighborhood. Based on the
existing grid street network that is found throughout Iowa City,
these small blocks will help to create a walkable district. Although
each block will have its own unique mix of uses, heights, and
frontages, the overall structure should be kept similar. Parking
should be placed on the interior of the blocks with buildings
around the perimeter.
The following pages represent a block by block analysis of the Sub-
Area Plan. The blocks are designed to allow for different densities
and configurations as the district transforms and the market
matures.
1
2
3
4 5
6 7
8 9
47
development block diagrams
As Riverfront Crossings begins to transition into a mixed-use neighborhood, it will be important to consider building use when designing
the site. The Plan uses three main building types: mixed-use, residential, and liner. Although these buildings are configured in a variety of
ways, the dimensions are similar throughout the Plan. It should be noted that these dimensions are provided as a guide for development,
and may vary depending on specific programmatic requirements. The diagrams below represent the typical dimensions shown in the
Riverfront Crossings Plan.
mixed-use building
Mixed-use buildings can vary in depth, depending on the uses
within. They typically range from 60’-70’ in depth. This dimension
accommodates ground-floor commercial as well as double-
loaded residential units on the upper levels. These residential
units are usually accessed by a lobby or central corridor with
elevator and/or stair access. Whereas a 60‘ depth may be ideal for
retail and residential, office floorplates are typically a minimum
of 80’ in depth and therefore may require a deeper building. For
that reason, it is important for the developer to coordinate the
proposed development program with the site.
residential building
Residential buildings are typically 65 -75’ in depth. This dimension
provides for a double-loaded corridor with units that have
access to sunlight and natural ventilation. Embedding garages
in residential buildings are a way to gain density in tighter areas
while also providing direct access from parking to units. The
levels with the embedded garage would have a single-loaded
corridor and residential units typically 35’-40’ in depth. If not used
for parking, the top of the garage can be used for outdoor living
space, including green roofs or patios for rear facing units.
liner building
Liner buildings are relatively shallow in depth and are used to
conceal parking structures and larger format retail stores. The
building depth can range from 20’-40’, depending on the tenant
or available area . The purpose of this type of building is to create
an active street frontage with shops, offices, and/or residential
units. Although larger businesses may find this building to be too
shallow to function, others, such as a cafes and specialty retailers,
find it appropriate. Residential liners are typically single-loaded to
provide adequate sunlight throughout the units, with a corridor
located to the rear, similar to units with an embedded garage.
DRAFT riverfront crossings sub-area plan48
block 1
heights
The building along Clinton Street will be 4-6
levels in height with a required stepback after
four levels.
frontages and setbacks
This building will have a 0’ retail setback with
canopy or awning frontage. This retail frontage
should turn the corner at Lafayette Street.
parking and access
Parking for the building will be located in an
embedded parking garage three levels in height
accessed by a drive off of Lafayette Street.
Angled on-street parking will be available on
Clinton Street with potential for parallel on-
street spaces where possible on Lafayette Street.
massing
A large mixed use building will define frontage
along Clinton Street. The parking garage should
be designed to define as much of Lafayette
Street as possible.
1
Lafayette Street
Cl
i
n
t
o
n
S
t
r
e
e
t
Ca
p
i
t
o
l
S
t
r
e
e
t
4
4
Lafayette Street
Cl
i
n
t
o
n
S
t
r
e
e
t
Ca
p
i
t
o
l
S
t
r
e
e
t
Lafayette Street
Cl
i
n
t
o
n
S
t
r
e
e
t
Ca
p
i
t
o
l
S
t
r
e
e
t
Clinton
S
t
r
e
e
t
L
a
f
a
y
e
t
t
e
S
t
r
e
e
t
Capitol Stree
t
Block 1
Area (acres)2.75
Residential SF 79,300
Retail/Office SF 15,250
Total SF 94,550
Residential Units 70
Parking Spaces 189
On-Street Parking 37
Residential - Creek 12’-16’ Setback
Residential 6’-10’ Setback
Commercial/Active 0’ Setback
On-Street Parking
Surface Parking
Parking Structures
Access
1 Level
2-3 Levels
4-6 Levels
7-13 Levels*
*max height contingent on ight zone
49
block 2
heights
A tower 7+ levels in height will be located at
the Benton Street/Capitol Street intersection
and along with the tower to the south, will be
a gateway for the area. A required stepback is
placed after six levels. The adjacent building
along Capitol Street will be 4-6 levels in height
with a required stepback at four levels. The
same constraints apply for the residential liner
building on Clinton Street. The Johnson County
Ambulance Center is designed to be 2-3 levels in
height at the corner of Benton Street and Clinton
Street.
frontages and setbacks
The residential tower at the intersection of
Benton and Capitol Streets will have ground
floor commercial with a 0’ setback and canopy or
awning frontage. The Ambulance Center should
also have a main pedestrian entrance at the
corner to activate the intersection. North along
Clinton Street and Capitol Street, buildings will
have a 6’-12’ residential setback with stoop or
dooryard frontages.
parking and access
Block 2 will be parked by a parking garage
lined by buildings along Capitol and Clinton
Streets. This parking garage will be three levels
in height. An access drive to the garage will be
located along Benton Street. Angled on-street
parking will be available along Clinton Street
with parallel parking along Benton Street and
Capitol Street wherever possible.
massing
The residential tower at the corner of Benton
and Capitol Streets will “hold” the corner with a
larger residential building fronting onto Capitol
Street. The Ambulance Center should also be
designed to “hold” the corner at Benton and
Clinton Streets. The apparatus bays should be
set back from Clinton Street.
Capitol
S
t
r
e
e
t
Clinton
S
t
r
e
e
t
Lafa
y
e
t
t
e
S
t
r
e
e
t
Be
n
t
o
n
S
t
r
e
e
t
Lafayette Street
Benton Street
Cl
i
n
t
o
n
S
t
r
e
e
t
Ca
p
i
t
o
l
S
t
r
e
e
t
4
4
4
6
Lafayette Street
Benton Street
Cl
i
n
t
o
n
S
t
r
e
e
t
Ca
p
i
t
o
l
S
t
r
e
e
t
Lafayette Street
Benton Street
Cl
i
n
t
o
n
S
t
r
e
e
t
Ca
p
i
t
o
l
S
t
r
e
e
t
2
Block 2
Area (acres)2.85
Residential SF 196,500
Retail/Office SF 37,200
Total SF 233,700
Residential Units 175
Parking Spaces 327
On-Street Parking 53
Residential - Creek 12’-16’ Setback
Residential 6’-10’ Setback
Commercial/Active 0’ Setback
On-Street Parking
Surface Parking
Parking Structures
Access
1 Level
2-3 Levels
4-6 Levels
7-13 Levels*
*max height contingent on ight zone
DRAFT riverfront crossings sub-area plan50
block 3
heights
Block 3 will contain pedestal buildings
punctuated by towers. One tower will be
located at the intersection of Benton and
Capitol Streets. Another tower will be located
mid-block on the Capitol/Kirkwood Connector.
These towers will have a required stepback after
six levels. The pedestal buildings adjacent to
the towers will be 4-6 levels in height with a
required stepback above four levels. A low-rise
residential building will be located at the Clinton
Street/Benton Street intersection.
frontages and setbacks
Residential towers along the Capitol Street/
Kirkwood Avenue connector street will have
ground floor commercial with a 0’ setback and
canopy or awning frontage. The rest of the block
will be designed with a 6’-10’ residential setback
that will allow for stoop or dooryard frontages.
parking and access
A three level parking garage will be located
mid-block and provide parking for the entire
development block. This garage should be
hidden by surrounding buildings. Access drives
will be sited along Clinton Street and Benton
Street to create a continuous street wall on
the Capitol Street/Kirkwood Avenue connector
street. Angled on-street parking will be available
along Clinton Street with parallel parking
on Benton Street and the Capitol/Kirkwood
Connector slip-lane.
massing
Large residential buildings will front onto the
Capitol/Kirkwood connector street with two
towers rising from this base. These buildings
would act as a gateway to the area and provide
extensive views of the river corridor and park.
Smaller residential buildings will front onto
Clinton and Benton Streets.
Clinto
n
S
t
r
e
e
t
Bent
o
n
S
t
r
e
e
t
Capi
t
o
l
S
t
r
e
e
t
4
4
4
4
6
6
Benton Street
Kirkwoood Avenue
Cl
i
n
t
o
n
S
t
r
e
e
t
Ca
p
i
t
o
l
S
t
r
e
e
t
Benton Street
Kirkwoood Avenue
Cl
i
n
t
o
n
S
t
r
e
e
t
Ca
p
i
t
o
l
S
t
r
e
e
t
Benton Street
Kirkwoood Avenue
Cl
i
n
t
o
n
S
t
r
e
e
t
Ca
p
i
t
o
l
S
t
r
e
e
t
3
Block 3
Area (acres)3.54
Residential SF 355,900
Retail/Office SF 19,800
Total SF 375,700
Residential Units 316
Parking Spaces 510
On-Street Parking 83
Residential - Creek 12’-16’ Setback
Residential 6’-10’ Setback
Commercial/Active 0’ Setback
On-Street Parking
Surface Parking
Parking Structures
Access
1 Level
2-3 Levels
4-6 Levels
7-13 Levels*
*max height contingent on ight zone
51
block 4
heights
A 4-6 level building will front onto Ralston
Creek, allowing views into the proposed park.
Buildings along Gilbert Street and the 1st Street
residential courtyard will be 2-3 levels in height.
frontages and setbacks
Buildings along Gilbert Street will have a 0’ retail
setback with canopy or awning frontage or a 6’-
10’ residential setback midblock. The residential
buildings along the 1st Street courtyard will
have a 6’-10’ setback that will allow for stoop
or dooryard frontage. Buildings fronting onto
Ralston Creek will have a designated creek
setback of 12’-16’. This setback is designed to
allow for a private sidewalk and stoop frontage.
parking and access
A three level parking garage is attached to
buildings fronting Ralston Creek and the 1st
Street residential courtyard. This garage will be
accessed by an alley that connects 1st Street
with Kirkwood Avenue. This alley will also
provide surface parking spaces for visitors.
Angled on-street parking will be located along
1st Street with parallel on-street spaces located
on Gilbert Street.
massing
A larger residential building will front onto
Ralston Creek and provide wide views of the
riverfront park. Smaller townhouses should
front onto the 1st Street courtyard. Gilbert
Street should be defined by lower rise mixed-
use buildings. Architectural treatments can
help define prominent corners along Kirkwood
Avenue and Gilbert Street.
4
4
Kirkwoood Avenue
1st Street
Gi
l
b
e
r
t
S
t
r
e
e
t
Kirkwoood Avenue
1st Street
Gi
l
b
e
r
t
S
t
r
e
e
t
Kirkwoood Avenue
1st Street
Gi
l
b
e
r
t
S
t
r
e
e
t
Gilbe
r
t
S
t
r
e
e
t
Kir
k
w
o
o
d
A
v
e
n
u
e
1
s
t
S
t
r
e
e
t
Block 4
Area (acres)2.02
Residential SF 94,400
Retail/Office SF 18,600
Total SF 113,000
Residential Units 85
Parking Spaces 172
On-Street Parking 15
Residential - Creek 12’-16’ Setback
Residential 6’-10’ Setback
Commercial/Active 0’ Setback
On-Street Parking
Surface Parking
Parking Structures
Access
1 Level
2-3 Levels
4-6 Levels
7-13 Levels*
*max height contingent on ight zone
DRAFT riverfront crossings sub-area plan52
block 5
heights
Buildings fronting onto Gilbert Street, 1st Street,
and Kirkwood Avenue should be 2-3 levels in
height.
frontages and setbacks
Buildings along Gilbert Street, 1st Street, and
Kirkwood Avenue will have a 0’ retail setback
with canopy or awning frontage. Along Gilbert
Street there is potential for midblock locations
to have a 6’-10’ residential setback.
parking and access
A surface parking lot concealed by buildings
from Gilbert Street and Kirkwood Avenue will
provide parking for the block. Access to the
parking lot will be provided by drives off of
Gilbert Street, 1st Street, Kirkwood Avenue, and
a new north/south access street connecting
Kirkwood Avenue to Highland Avenue. Angled
on-street parking will be located along 1st Street
with parallel parking spaces on Gilbert Street
and Kirkwood Avenue where possible.
massing
Low-rise mixed-use buildings should define
Gilbert Street, 1st Street, and Kirkwood Avenue.
Enhanced architectural treatment should occur
at the corners of Gilbert Street and 1st Avenue
and Kirkwood Avenue.
5
1st Street
Kirkwoood Avenue
Gi
l
b
e
r
t
S
t
r
e
e
t
1st Street
Kirkwoood Avenue
Gi
l
b
e
r
t
S
t
r
e
e
t
1st Street
Kirkwoood Avenue
Gi
l
b
e
r
t
S
t
r
e
e
t
Gilbert
S
t
r
e
e
t
K
i
r
k
w
o
o
d
A
v
e
n
u
e
1s
t
S
t
r
e
e
t
Block 5
Area (acres)2.62
Residential SF 44,400
Retail/Office SF 31,400
Total SF 75,800
Residential Units 40
Parking Spaces 129
On-Street Parking 35
Residential - Creek 12’-16’ Setback
Residential 6’-10’ Setback
Commercial/Active 0’ Setback
On-Street Parking
Surface Parking
Parking Structures
Access
1 Level
2-3 Levels
4-6 Levels
7-13 Levels*
*max height contingent on ight zone
53
block 6
heights
Buildings 4-6 levels in height will front onto
Ralston Creek and the park with a required
stepback after four levels. Buildings along
Gilbert Street and portions of the residential
courtyard will be 2-3 levels in height.
frontages and setbacks
Buildings along Gilbert Street will have a 0’
retail setback with canopy or awning frontage.
or a 6’-10’ residential setback located midblock.
The residential buildings along both residential
courtyards will have a 6’-10’ setback that will
allow for stoop or dooryard frontage. Buildings
fronting onto Ralston Creek will have a
designated creek setback of 12’-16’. This setback
will be designed to allow for a private sidewalk
and stoop frontage.
parking and access
A four level parking garage located mid-block
will provide parking for the development block.
This garage should be hidden on all sides by
buildings and accessed by an alley running
north/south. This alley will be accessed off of 1st
Street and a new street located on the south side
of the block. This alley will also provide surface
parking spaces for visitors. Angled on-street
parking will be located along 1st Street and the
new street, with parallel on-street spaces located
along Gilbert Street.
massing
Larger residential building will front onto
Ralston Creek to give wide views of the
riverfront park. Smaller townhouses should front
onto the northern and southern courtyards.
Gilbert Street should be defined by lower rise
mixed-use buildings. Enhanced architectural
treatment should define the corners of 1st Street
and the new street off of Gilbert Street.
Gilbert
S
t
r
e
e
t
1s
t
S
t
r
e
e
t
4
4
1st Street
Gi
l
b
e
r
t
S
t
r
e
e
t
1st Street
Gi
l
b
e
r
t
S
t
r
e
e
t
1st Street
Gi
l
b
e
r
t
S
t
r
e
e
t
6
Block 6
Area (acres)3.14
Residential SF 156,100
Retail/Office SF 24,200
Total SF 180,300
Residential Units 139
Parking Spaces 348
On-Street Parking 24
Residential - Creek 12’-16’ Setback
Residential 6’-10’ Setback
Commercial/Active 0’ Setback
On-Street Parking
Surface Parking
Parking Structures
Access
1 Level
2-3 Levels
4-6 Levels
7-13 Levels*
*max height contingent on ight zone
DRAFT riverfront crossings sub-area plan54
block 7
heights
Buildings fronting onto Gilbert Street and 1st
Street should be 2-3 stories in height.
frontages and setbacks
Buildings along Gilbert Street and 1st Street will
have a 0’ retail setback with canopy or awning
frontage or a 6-10’ residential setback midblock.
parking and access
A surface parking lot concealed by buildings
from Gilbert Street and 1st Street will provide
parking for the block. Access to the parking lot
will be provided by drives off of Gilbert Street,
1st Street and by a new north/south access
street connecting Kirkwood Avenue to Highland
Avenue. Angled on-street parking will be located
along 1st Street with parallel parking on Gilbert
Street.
massing
Low-rise, mixed-use buildings should define
Gilbert Street and 1st Street. Enhanced
architectural treatment should define the corner
of Gilbert Street and 1st Street.
7
1st Street
Gi
l
b
e
r
t
S
t
r
e
e
t
1st Street
Gi
l
b
e
r
t
S
t
r
e
e
t
1st Street
Gi
l
b
e
r
t
S
t
r
e
e
t
Gilbert
S
t
r
e
e
t
1st
S
t
r
e
e
t
Block 7
Area (acres)2.59
Residential SF 44,000
Retail/Office SF 27,900
Total SF 71,900
Residential Units 40
Parking Spaces 164
On-Street Parking 24
Residential - Creek 12’-16’ Setback
Residential 6’-10’ Setback
Commercial/Active 0’ Setback
On-Street Parking
Surface Parking
Parking Structures
Access
1 Level
2-3 Levels
4-6 Levels
7-13 Levels*
*max height contingent on ight zone
55
block 8
heights
Block 8 should be developed with buildings
2-3 levels in height. This block is located in the
flight path of the Iowa City Municipal Airport
and therefore is regulated by Federal Aviation
Administration (FAA) height restrictions.
frontages and setbacks
Buildings along Gilbert Street will have a 0’ retail
setback with canopy or awning frontage or a
6’-10’ residential setback midblock. Residential
courtyard buildings will have a 6’-10’ setback
that would allow for stoop or dooryard frontage.
Buildings fronting onto Ralston Creek will have a
designated creek setback of 12’-16’. This setback
will be designed to allow for a private sidewalk
and stoop frontage.
parking and access
Parking for this block will be located in a large
surface parking lot located mid-block. This
parking should be concealed from Gilbert Street
by liner buildings and accessed by drives located
off of Gilbert Street and the new east/west street
located to the north of the block. Townhouses
fronting onto the courtyard will have tuck-under
garage spaces accessed by an alley to the rear of
the buildings. Angled on-street parking will be
located on the new street.
massing
Low-rise, mixed-used buildings should define
Gilbert Street, the residential courtyard and
Ralston Creek. Enhanced architectural treatment
can help define the corners of U.S. Highway 6
and the new street off of Gilbert Street. The U.S.
Highway 6 intersection should include an entry
feature into the new district from the south.
8
Highwa
y
6
Gi
l
b
e
r
t
S
t
r
e
e
t
Highwa
y
6
Gi
l
b
e
r
t
S
t
r
e
e
t
Highwa
y
6
Gi
l
b
e
r
t
S
t
r
e
e
t
Gilb
e
r
t
S
t
r
e
e
t
Highwa
y
6
Block 8
Area (acres)3.29
Residential SF 84,200
Retail/Office SF 17,400
Total SF 107,400
Residential Units 70
Parking Spaces 160
On-Street Parking 5
Residential - Creek 12’-16’ Setback
Residential 6’-10’ Setback
Commercial/Active 0’ Setback
On-Street Parking
Surface Parking
Parking Structures
Access
1 Level
2-3 Levels
4-6 Levels
7-13 Levels*
*max height contingent on ight zone
DRAFT riverfront crossings sub-area plan56
block 9
heights
The liner building along Gilbert Street should
be 2-3 levels in height, with the small box retail
store being one level. This block is located in the
flight path of the Iowa City Municipal Airport
and therefore is regulated by Federal Aviation
Administration (FAA) height restrictions.
frontages and setbacks
The building fronting onto Gilbert Street should
have a 0’ retail setback with canopy or awning
frontage or a 6’-10’ residential setback midblock.
parking and access
Parking for this block will be located in a surface
parking lot located at the corner of Highland
Avenue and Gilbert Street. This parking lot
should be accessed by drives off of Highland
Avenue, Gilbert Street, and a new north/
south street connecting Kirkwood Avenue to
Highland Avenue. This parking lot should be well
concealed from Gilbert Street using landscape
and architectural treatments. An access drive to
the north should be used for loading/service for
the small box store.
massing
Liner buildings should be used to establish an
active frontage along Gilbert Street. Enhanced
architectural treatment should be provided on
the southwest corner of the small box store.
The small box retail store should be enhanced
to give a more pedestrian scale and character
that would correspond with the rest of the
development.
Highland Avenue
Gi
l
b
e
r
t
S
t
r
e
e
t
Highland Avenue
Gi
l
b
e
r
t
S
t
r
e
e
t
Highland Avenue
Gi
l
b
e
r
t
S
t
r
e
e
t
Gil
b
e
r
t
S
t
r
e
e
t
Hig
h
l
a
n
d
A
v
e
n
u
e
9
Block 9
Area (acres)2.97
Residential SF 0
Retail/Office SF 42,500
Total SF 42,500
Residential Units 0
Parking Spaces 153
On-Street Parking 0
Residential - Creek 12’-16’ Setback
Residential 6’-10’ Setback
Commercial/Active 0’ Setback
On-Street Parking
Surface Parking
Parking Structures
Access
1 Level
2-3 Levels
4-6 Levels
7-13 Levels*
*max height contingent on ight zone
57
yield analysis summary
Area (acres)Residential SF Retail/Office SF Total SF Residential Units Parking Spaces On-Street
Parking
Block 1 2.75 79,300 15,250 94,550 70 189 37
Block 2 2.85 196,500 37,200 233,700 175 327 53
Block 3 3.54 355,900 19,800 375,500 316 510 83
Block 4 2.02 94,400 18,600 113,000 85 172 15
Block 5 2.62 44,400 31,400 75,800 40 129 35
Block 6 3.14 156,100 24,200 180,300 139 348 24
Block 7 2.59 44,000 27,900 71,900 40 164 24
Block 8 3.29 84,200 17,400 107,400 70 160 5
Block 9 2.97 0 42,500 42,500 0 153 0
Total 25.77 1,060,600 234,250 1,294,850 935 2,152 276
Park 25.99
ROW 25.04
Total Area 76.80
A summary of the development potential for the Riverfront
Crossings Sub-Area is listed below. Green space accounts for
roughly the same amount of land as private development, creating
an attractive ratio for residents and visitors. The total commercial
space in the plan is aggressive, and should be modified as market
conditions change.
Parking Ratios
Parking Ratios used for analysis purposes:
Residential - 1.5 spaces/unit
Retail/Office - 3.65 spaces/1000 SF
DRAFT riverfront crossings sub-area plan58
59
next steps
DRAFT riverfront crossings sub-area plan60
development code
Using the design guidelines provided in this document as a base,
a form-based code or hybrid code should be created for the Sub-
Area. This code would guide the transition of the study area into
the mixed-use, pedestrian-oriented district that is envisioned. The
code would be graphic in nature and would prescribe standards
for building form (which includes placement and orientation),
use, frontages and setbacks, parking placement, and public
space standards, which includes regulation of sidewalks and
thoroughfares.
detailed traffic study
This study would conduct existing traffic counts and assess future
traffic growth, pass-by trips, internal trip reduction and transit
usage. The study intersections would be considered as part of
a network of intersections in order to assess traffic signal cycle
lengths and coordination. Micro-simulation analysis, in addition
to Synchro, would help determine design recommendations such
as storage bay lengths. In order to assess safety, crash analysis and
bicycle/pedestrian traffic should also be a part of any additional
study.
integrated stormwater master plan
This master plan would incorporate ecological and engineering
principles to simultaneously address both water quantity and water
quality, with an emphasis on the consideration of the full water
cycle; infiltration-based techniques; multi-use landscape features,
including recreation and wildlife habitat; and education and
outreach opportunities.
creek and habitat restoration plan
This plan should focus on soft stabilization of the stream bank,
protecting water quality, and restoring the riparian corridor with
native species. This plan should be coordinated with the Integrated
Stormwater Master Plan.
park master plan
As the North Wastewater Treatment Plant is relocated, a Park
Master Plan should be created to formalize ideas created during
this Sub-Area Master Plan. This Park Master Plan would establish a
more in-depth development plan for the riverfront park, creating
construction documents within a specified budget. All effort should
be made to incorporate the Integrated Stormwater Master Plan and
the Creek and Habitat Restoration Plan with this new Park Master
Plan.
existing business placement
As the Sub-Area transitions from industrial and commercial to a
mixed-use, pedestrian-oriented neighborhood, tools and strategies
should be developed to help existing businesses remain in the
area or assist them in finding new locations that better meet their
business goals.
affordable housing
The Riverfront Crossings District has the opportunity to provide a
mix of housing that is both mixed-income and mixed-age. As plans
for the District move forward, potential development incentives
and policy options should be discussed to provide affordable
housing within the district.
parking facilities
Parking within the Riverfront Crossings District should be based
on a district approach. Shared parking, demand pricing, and
parking structures can play a key role. As development within the
district begins to occur, key policy decisions relating to parking
management and the provision of parking facilities must be
addressed.
block 4
61
appendices
DRAFT riverfront crossings sub-area plan62
appendix a: auto-oriented uses
In Milwaukee, WI, this mixed-use gas station locates the convenience store on the ground floor with office above.
On the periphery of pedestrian-oriented, mixed-use districts, it may be possible to have utilitarian type
uses. Where these auto-oriented uses, such as gas stations, drive-thru restaurants, pharmacies, and
banks are proposed, they will need to be designed in a pedestrian-oriented nature. Principal buildings
should meet setback and build-to requirements and have prominent street-side pedestrian entrances
with vehicular use areas properly designed and located behind buildings or along secondary
frontages. These types of enhancements maintain the desired aesthetic and pedestrian-orientation
of the area. In particular, these types of uses should not be located along frontages designated as
warranting enhanced façades or detract from important pedestrian routes or residential frontages.
Because access is important, they are often sited on corner lots.
The plan and photo here show examples of how gas stations can be contextually designed to front
onto the street and activate the corner. One potential location for a gas station in the Sub-Area is the
small box store site at the northeast corner of the intersection of Gilbert Street and Highland Avenue.
This site is highly visible and provides easy vehicular access. The ‘gas backwards’ concept shown
positions the pumps behind the convenience store, which fronts onto Gilbert Street and Highland
Avenue. Pedestrian access to the store is provided from both the street and the pumps. The concept
to the right shows a smaller retail box footprint with additional parking located to the east of the
building.
Pumps
Customer Entrances
Convenience
Store
Canopy
Google Maps
63
HDR Engineering, Inc.8404 Indian Hills Drive Omaha, NE 68114-4098 Phone (402) 399-1000 Fax (402) 399-4979 www.hdrinc.com
Page 1 of 8
MemoTo: Doug Bisson
From: Jeff Riesselman Project: Riverfront Crossings District
CC:Eric Pohlmann
Date: November 4, 2010 Job No: 146303
RE: Planning Level Traffic Evaluation for Riverfront Crossings District – Iowa City, IA
Introduction
The purpose of this memorandum is to document the traffic evaluation of the Riverfront Crossings
District in Iowa City, Iowa. This is a planning-level assessment of the street options related to the current Riverfront Crossings District development concept as of October 29, 2010. The evaluation focuses on four key intersections shown in Figure 1 below. Also, there are two street concepts that are studied. The first is a one-way concept that provides counter-clockwise circulation around
Dubuque Street, Benton Street, Capitol Street and Kirkwood Avenue (similar to current operations). The second concept makes all these streets two-way operations.
Figure 1 – Study Intersections
Study Intersection
Kirkwood Ave
Benton St
Hwy 6
Capitol
St
Clinton
St
Dubuque
St
Gilbert
St
HDR Engineering, Inc.8404 Indian Hills Drive Omaha, NE 68114-4098 Phone (402) 399-1000 Fax (402) 399-4979 www.hdrinc.com
Page 2 of 8
Data Collection
Traffic counts were provided by the City of Iowa City at the four key study intersections during the AM and PM peak hours. In addition, signal timing information was provided at the Gilbert Street/Kirkwood Avenue intersection which is split-phased in the NB/SB directions. Lane
configurations and signal phasing were determined by using aerials and photos available from Google and Bing maps.
Existing Conditions
Synchro analysis for existing conditions was necessary in order to establish a base-line for comparison of the conceptual plan traffic operations. Cycles and splits were assumed at Gilbert St/Highway 6 and Capitol St/Benton St. Even though analysis was completed for both the AM and
PM peak hours; the PM peak hour was the controlling time period. For purposes of this planning level traffic evaluation, only PM results are presented.
• Capitol St/Benton St Æ LOS A
• Gilbert St/Benton St Æ LOS E (worst-case stop-controlled approach)
• Gilbert St/Kirkwood Ave Æ LOS D
• Gilbert St/Highway 6 Æ LOS D
Development Trips
The development is broken up into two areas as shown in Figure 1. The Capitol Area has a total of
682 residential units, 35,000 square feet of office and 30,000 square feet of retail. The Gilbert Area has 498 residential units, 35,000 square feet of office and 80,000 square feet of retail. The high-rise condo, general office and specialty retail development categories were utilized in the ITE Trip
Generation Handbook.
Below is a list of assumptions related to trip generation and assignment:
• Assumed lower than average vehicle trip rates for residential because of the existence of light rail and bicycle commuter emphasis
• Assumed no reduction of trips for existing land uses that would be removed as part of the
new development
• Assumed no pass-by trips or internal trip reduction
• Assumed no future background traffic growth in the area
• Assumed Capitol area trips destined to/from the east side of the Iowa River would cross the Benton Street bridge
• Assumed only a small number of trips through the Gilbert Street/Benton Street stop-
controlled intersection because it is approaching LOS F
• Assumed all Gilbert area trips access the development to/from Gilbert Street.
Overall the assumptions provide a conservative assessment of the traffic volumes. The table on the next page provides a summary of the trip generation results. Figure 2 and Figure 3 show the one-way and two-way concept build traffic volumes, respectively.
appendix b: conceptual transportation analysis
HDR Engineering, Inc.8404 Indian Hills Drive Omaha, NE 68114-4098 Phone (402) 399-1000 Fax (402) 399-4979 www.hdrinc.com
Page 1 of 8
Memo
To: Doug Bisson
From: Jeff Riesselman Project: Riverfront Crossings District
CC:Eric Pohlmann
Date: November 4, 2010 Job No: 146303
RE: Planning Level Traffic Evaluation for Riverfront Crossings District – Iowa City, IA
Introduction
The purpose of this memorandum is to document the traffic evaluation of the Riverfront Crossings
District in Iowa City, Iowa. This is a planning-level assessment of the street options related to the current Riverfront Crossings District development concept as of October 29, 2010. The evaluation focuses on four key intersections shown in Figure 1 below. Also, there are two street concepts that are studied. The first is a one-way concept that provides counter-clockwise circulation around
Dubuque Street, Benton Street, Capitol Street and Kirkwood Avenue (similar to current operations). The second concept makes all these streets two-way operations.
Figure 1 – Study Intersections
Study Intersection
Kirkwood Ave
Benton St
Hwy 6
Capitol
St
Clinton
St
Dubuque
St
Gilbert
St
DRAFT riverfront crossings sub-area plan64
HDR Engineering, Inc.8404 Indian Hills Drive Omaha, NE 68114-4098 Phone (402) 399-1000 Fax (402) 399-4979 www.hdrinc.com
Page 3 of 8
Table 1 – Trip Generation
Figure 2 – One-Way Build Volumes
HDR Engineering, Inc.8404 Indian Hills Drive Omaha, NE 68114-4098 Phone (402) 399-1000 Fax (402) 399-4979 www.hdrinc.com
Page 4 of 8
Figure 3 – Two-Way Build Volumes
Findings
One-Way vs. Two-Way Concept
The operations within the area bordered by Dubuque Street, Benton Street, Capitol Street and Kirkwood Avenue are acceptable regardless of the one-way or two-way operations. The Capitol Street/Benton Street intersection would operate at LOS B for both concepts. The one-way concept
would consist of two-lanes in the counter-clockwise circulation area, as exists today. The two-way
concept would operate with acceptable operations if all streets in this area were only two-lane streets. However, it is recommended that Kirkwood Avenue from Benton Street to Gilbert Street be three-lanes for increased capacity and an appearance as the primary route.
The two-way concept provides superior access alternatives in the Capitol development area when compared to the one-way concept. However, the one-way concept provides slightly better operations at the Capitol/Benton intersection and naturally diverts traffic away from the Gilbert
St/Benton St stop-controlled intersection. The two-way concept could make the Gilbert St/Benton
St intersection more appealing to drivers. Our study assumed minimal traffic would use Benton Street because of the poor operations from the stop-controlled approaches at Gilbert Street. However, this intersection nearly meets a peak-hour signal warrant. If a signal were installed, it would improve traffic operations but would attract additional traffic to Benton Street which the City
has indicated as undesirable.
Gilbert Street/Kirkwood Avenue
Regardless of the one-way or two-way concepts, this intersection would operate at LOS F with
development traffic assigned. The intersection currently operates at LOS D. The NB/SB split-phase operations (necessary because there are no left-turn lanes present) are very inefficient. Left-turn lanes would be recommended.
65
HDR Engineering, Inc.8404 Indian Hills Drive Omaha, NE 68114-4098 Phone (402) 399-1000 Fax (402) 399-4979 www.hdrinc.com
Page 5 of 8
The peak hour and daily traffic volumes on Gilbert Street would exceed the threshold for a three-
lane section with a two-way center left-turn lane. A five-lane section would be recommended.
Gilbert Street/Highway 6Regardless of the one-way or two-way concepts, this intersection would operate at LOS E with
development traffic assigned. The intersection currently operates at LOS D. If the left-turn phases were changed to “permitted/protected” operations in all four directions, then the intersection would continue to operate at LOS D. However, the left-turn phases should remain “protected only” if safety issues preclude the use of permitted left-turns. Assuming that is the case, some other kind
of capacity improvement would be required. Dual-left turn lanes in the NB and SB directions and a SB right turn lane would provide improved operations from the current conditions.
Recommendations
One-Way vs. Two-Way ConceptOther factors should influence this decision such as access management. The traffic operations are acceptable no matter which concept moves forward. But, each concept provides different lane
configurations in the area (i.e. Capitol/Benton intersection). Figure 4 and Figure 5 are screen captures of the Synchro networks showing what the recommended lane configurations should be for each concept. If it is highly desirable to keep the Gilbert Street/Benton Street intersection unsignalized, then the one-way concept would favor over the two-way concept. However, there are
other ways to control the traffic on Benton Street to keep traffic levels below signal warrant levels.
Figure 4 – One-Way Recommended Lane Configurations
HDR Engineering, Inc.8404 Indian Hills Drive Omaha, NE 68114-4098 Phone (402) 399-1000 Fax (402) 399-4979 www.hdrinc.com
Page 6 of 8
SUDAS Minimum Criteria: For the one-way concept, all lane widths should be 12 feet except:
• Capitol Street north of Benton Street Æ 11 feet
• Clinton Street Æ 11 feet
• Dubuque Street north of Benton Street Æ 11 feet
Figure 5 – Two-Way Recommended Lane Configurations
SUDAS Minimum Criteria: For the two-way concept, all lane widths should be 12 feet except:
• Capitol Street north of Benton Street Æ 11 feet
• Clinton Street Æ 11 feet
• Dubuque Street Æ 11 feet
• Benton Street east of Capitol Street Æ 11 feet
• Two-Way Left-Turn Lane on Capitol/Kirkwood Connector Æ 14 feet
DRAFT riverfront crossings sub-area plan66
HDR Engineering, Inc.8404 Indian Hills Drive Omaha, NE 68114-4098 Phone (402) 399-1000 Fax (402) 399-4979 www.hdrinc.com
Page 7 of 8
Gilbert Street
As previously mentioned, Gilbert Street will not be able to function as a three-lane roadway. Without left-turn lanes on Gilbert Street, the Kirkwood Avenue signal would have to remain split phased and would provide LOS F operations. The addition of NB/SB left-turn lanes and an EB right-turn lane would provide LOS C operations. Gilbert Street should be a five-lane roadway with a
two-way center left-turn lane that would eliminate the need for split phasing at Kirkwood, but would also provide a lane for which development trips to turn from. North of Kirkwood Avenue, Gilbert Street could transition back to a four-lane roadway assuming Benton Street remains unsignalized.
Figure 6 – Gilbert Street Lane Configurations (north pointing to the right)
SUDAS Minimum Criteria: For the Gilbert Street area, all lane widths should be 12 feet except:
• Two-Way Left-Turn Lane on Gilbert Street Æ 14 feet
• Benton Street Æ 11 feet
Highway 6Highway 6 operations would carry additional trips due to the development. The current operations
at Gilbert Street/Highway 6 are LOS D. The addition of development trips would reduce the
operations to LOS E. As previously mentioned, the left-turn phases are all protected only phases. If they were updated to permitted/protected phasing, operations would improve back to LOS D. Assuming the left-turn phases must remain protected only, other capacity improvements would be
necessary. The construction of dual-left turn lanes in the NB and SB directions would improve
operations back to existing LOS D levels. The addition of a SB right turn lane provides further improvement. If after those improvements dual left-turn lanes were also provided in both directions on Highway 6 (as depicted in the Engineering Alliance, Inc. conceptual drawing – 2005), the
operations would improve to LOS C. The minimal recommendation for improved operations would
be dual left-turn lanes in the NB and SB directions and a SB right turn lane.
HDR Engineering, Inc.8404 Indian Hills Drive Omaha, NE 68114-4098 Phone (402) 399-1000 Fax (402) 399-4979 www.hdrinc.com
Page 8 of 8
Figure 7 – Highway 6 Lane Configurations
SUDAS Minimum Criteria: For the Highway 6 area, all lane widths should be 12 feet.
Additional Study
It should be noted that all recommendations in this memo are planning level recommendations. Further study is needed prior to design of any street improvements or redevelopment in order to
fine tune the assumptions of this memo (density, access, transit options, etc.) and to discuss the
feasibility of the planning level recommendations. The study would conduct existing traffic counts and assess future traffic growth, pass-by trips, internal trip reduction and transit usage. The study intersections would be considered as part of a network of intersections in order to assess traffic
signal cycle lengths and coordination. Micro-simulation analysis, in addition to Synchro, would help
determine design recommendations such as storage bay lengths. Crash analysis and pedestrians should also be part of any additional study in order to assess safety.
Typically, a detailed traffic impact study is conducted during the design phase of any proposed
development. At that time, specific information regarding the type of development will be known, including proposed access locations. In some cases, local street improvement projects precede redevelopment projects. The details of the study should not change, but every effort should be
made to make accurate assumptions that are documented and approved by the stakeholders.