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HomeMy WebLinkAboutStreetscape componentsIOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 32 [ PAGE INTENTIONALLY LEFT BLANK ] FEBRUARY 2014 33 S t r e e t s c a p e C o m p o n e n t s SECTION 4 Streetscape Components IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 34 The City’s existing banner program includes the streets of Clinton, Washington, Dubuque, and Linn. Banners announce the farmer’s market and other special events. The City’s standard banner size is 30” Wide by 84” Long. ROLE IN URBAN AREAS A clear wayfinding system is an essential component of cities and college towns and helps users understand the complexities of a new and changing environment. A suc- cessful wayfinding and identity framework makes the en- vironment ‘legible’ and enhances the users’ experiences. It builds their confidence and comfort level while encour- aging them to discover the adjacent context and destina- tions. The legibility offered through a consistent and highly functioning framework heightens the enjoyment and ap- peal of a place. The existing kiosks and posting pillars date from the 1998 Downtown Streetscape Phase I Improvements and many are showing their age. Bases are deteriorating, they are filled with newspaper machines and pay phones, and no longer meet their intended purposes. Additionally, they feel over-sized and crowd the streetscape. DESIGN PROCESS The site assessment revealed an existing wayfinding frame- work in need of an update. The intent was to give the user a more simplified experience while providing the streets- capes with a fresh, new look. As part of the planning pro- cess, three options were prepared and reviewed with the public and stakeholder groups: “I see”, the metal fabric option and the spine of a book. The metal fabric option was preferred and includes a family of signage elements that echo the solid architecture and organization in the City. Using large type, solid, substantial forms and patterns, the program reminds the viewer where they are and what is around them at key opportunities. The concept ensures consistency and recognizability and can be adapted and altered as required for specific locations and messages. COMPONENTS | WAYFINDING + IDENTITY EXISTING KIOSKS AND POSTING PILLARS EXISTING BANNERS FEBRUARY 2014 35 The preferred option, metal fabric, uses large type and patterning to inform use. The names of the streets and intersections make up the formal structure of the metal screens that support the information. The use of large type and patterning affords opportunities to incorporate multi-ple languages into the wayfinding elements. The spine of a book acts as an introduction to the informa-tion contained inside. Well read and hitching a ride on the notion of a book, this family of wayfinding elements stands waiting to have its pages of information turned. The icon says Iowa City is woven into everything in the public realm. A fabric of Iowa City wraps signage banners and furniture in its typographic identity. Internally illuminat-ed, the wayfinding elements become beacons of light and information during the nighttime hours. The icon reads as “information” at first glance. Then the viewer sees the “c” in the dot over the i. The resulting graphic says information and when said aloud - “I see”. It’s fun and casual in its different colors and accessible to everyone. OPTION C THE PREFERRED OPTION OPTION B OPTION A WAYFINDING CONCEPTS COMPONENTS | WAYFINDING + IDENTITY IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 36 Gateway element Banners support the designs of the rest of the signage package. Color, patterns and slight motion add to the pageantry of the street. A primary banner program is proposed along Iowa Avenue and Clinton. Banners create a feeling that things are happening and changing every time a new design goes up. A second-ary banner program is proposed along Burlington and Gilbert and are sized to accommodate the City stan-dard banner size. The Gateway Elements serve as monumental thresholds in concert with the street scape elements that let the vis- itor know something is different, improved and special. They are walking in a new place with new colors, materi- als and illuminated information. The Wayfinding Kiosks are beacons of light, type and in- formation constructed from substantial materials at a pe- destrian scale. Information is here, and easy to access. Kiosks are spaced in the downtown so that a visitor will leave one and see the next one soon - creating a “trail of bread crumbs” to the next destination. Primary banner program Secondary banner program Wayfinding kiosk COMPONENTS | WAYFINDING + IDENTITY FEBRUARY 2014 37 WAYFINDING KIOSK SECONDARY BANNER PROGRAM PRIMARY BANNER PROGRAM GATEWAY ELEMENT WAYFINDING + IDENTITYA family of signage elements has been designed to in-clude gateway elements, wayfinding kiosks, and banners. The elements are strategically located to improve legibility and to ease navigation between destinations. Note: Refer to page 34 for identification of wayfinding and identity el-ements. COMPONENTS | WAYFINDING + IDENTITY IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 38 The bell-shaped lights have become the City standard across downtown. They have been installed along Bur-lington Street, Iowa Avenue, Linn Street and along Mar-ket and North Linn at the Northside Marketplace. Many have been converted to LED. Additionally, the University of Iowa has been installing the bell-shaped lights along the Iowa River Corridor Trail. Many of the limestone light pole bases along Iowa Avenue are starting to deteriorate. Other light pole assem-blies along the streetscapes are in a state of decline and are nearing the end of their serviceable life, or need signif-icant maintenance and conversion to LED. A mix of lighting exists across the study area. The majority of street lighting consists of cobra head style fixtures or shoe box fixtures of varying colors: Black, green, red, blue grey. ROLE IN URBAN AREA Quality lighting is essential to the success and comfort of urban areas. It is a key organizing element that defines the nighttime visual environment and helps create a down- town identity. Visitors and residents should recognize they are within downtown Iowa City by the character of the streetscape lighting. The lighting contributes to a safe, at- tractive environment and encourages and supports night- time use. DESIGN PROCESS The site assessment revealed an aging lighting system and a mix of lighting styles. There are significant opportunities for a multi-layered, flexible lighting framework that will reflect a cohesive, sustainable and contemporary destination. The proposed lighting design calls for a family of pole and monumental lights to be placed appropriately within the city’s hierarchy of streets. The design concept takes con- textual design cues from Iowa City itself. The bracket arms of the standard street lights are informed by the dome and cornice of the Old State Capitol. The bell-shaped skirt has been incorporated to ensure consistency across the study area and to afford re-use of the City standard. STREETSCAPE COMPONENTS | LIGHTING + ELECTRICAL BELL-SHAPED LIGHTS EXISTING LIGHTS EXISTING CONDITIONS FEBRUARY 2014 39 A consistent family of lights that builds off of the existing Bell-shaped light is proposed across Downtown. The bracket arms mimic the dome and cornice of the old state capitol A FAMILY OF LIGHTSThe family can be separated into two types: ‘standard’ metal pedestrian and roadway lights as well as ‘monu-mental’ limestone base and lights. Within the study area, the ‘standard’ lights are recommended for the streets of Burlington, Washington, College, Bloomington, Gilbert, Market, Linn and North Linn. The ‘monumental’ light bas-es are made of Iowa limestone, the familiar material seen throughout the city and state and are recommended for the streets of Dubuque, Clinton, and Iowa. On Dubuque Street overhead arms with Tivoli lights and medallions are added to the monumental lights to help create a canopy or perceived ceiling. Banners can easily be integrated to the standard poles to fit the recommendations of the signage and wayfinding plan. Large celebratory banners are incorporated into the design of the monumental lights along Clinton Street and Iowa Avenue, while decorative metal screens fitting in with the recommended wayfinding elements are integrated with the monumental lights at Washington and Dubuque. STREETSCAPE COMPONENTS | LIGHTING + ELECTRICAL IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 40 STREETSCAPE COMPONENTS | LIGHTING + ELECTRICAL The lighting framework proposes layers of lighting to add dimension and interest. Consistent, ample illumination is provided along the sidewalk and enhanced storefront lighting adds depth to the public realm. Full cutoff fixtures focus the light directly downward to reduce light pollution. Grapevine sphere lights previously hung in the trees throughout the Ped Mall have been re-located by ICDD to illuminate the passageway adjacent to the Sheraton Hotel. The unique and memorable lighting enhances the sense of safety at a previously dark and under-lit passage-way. Expanded use of the spheres across the alleys inter-secting with the Ped Mall is recommended. ALLEY LIGHTING CHARACTER OF LIGHTING FRAMEWORK LAYERS OF LIGHTING Lighting is not limited to the functional lighting of streets and sidewalks. Layers of architectural lighting, light art, fes- tive street lighting and improved illumination of the alleys is proposed to add drama and energy across the study area. FEBRUARY 2014 41 ENHANCED STOREFRONT LIGHTING ARCHITECTURAL LIGHTING ILLUMINATED WAYFINDING KIOSK AND GATEWAY ELEMENT IDENTITY LIGHTING ALONG MARKET STREET Light art and unique architectural lighting can be used to activate the blank facades along Burlington and the Linn Street walkway to the Northside Marketplace At night the screens would be illuminated and serve as a glowing marker to people in search of information. Property owners along Clinton, Iowa Avenue, Linn Street, Dubuque, and Washington are encouraged to enhance their storefront lighting through various methods like up or down lighting and lit signage Identity lighting is proposed along Market Street to distin-guish the Northside Marketplace. Visible from Dubuque, the festive lighting creates a sense of arrival to the desti-nation STREETSCAPE COMPONENTS | LIGHTING + ELECTRICAL IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 42 Electrical distribution Option 1. New electrical distribution bollards are proposed along Iowa Avenue and Clinton to provide permanent power connections for vendors. Two (2) locations would be identified on each side of the street to match distribu-tion locations used for temporary generators. Any new electrical distribution will require new underground con-duit. Horizontal directional boring may be an option, but conflicts with existing underground utilities may make this impractical. The new distribution bollards can be connect-ed to the existing electrical panel located adjacent to the west utility transformer on the south side of Iowa Ave. Rec-ommendations are based on visual assessments only. A site survey for verification is required as part of subsequent design phases. The electrical bollards offer up to 8 circuits/box and are customizable. At the proposed two per each side of the street, the capacity would be comparable to or could ex-ceed the power offered by the two temporary generators used during the June 2013 Iowa Arts Festival. Option 2. Electrical capacity can be included at the new monumental limestone base as proposed along Iowa Av-enue and Clinton. Four electrical outlets are proposed per monument light base. OTHER OBSERVATIONS AND RECOMMENDATIONSIt appears that circuits for the tree well receptacles and light poles are installed in the same conduits. This is not ideal for adding more capacity at existing locations. It may be possible to add circuits, but existing conduits can-not handle enough extra power to accommodate all fes-tival vendors. Consideration should be given to relocating portable generators away from vendors to minimize noise and fume issues. LIGHTING TECHNOLOGY Over the past few years, the City has been converting their existing system to light-emitting diode (LED) lighting. Because of the enhanced lighting efficacies LED offers, a move toward full conversion across the study area is rec- ommended. Full cut-off LED lighting and programmable controls offer vast improvements in light pollution, energy efficiency, and operational cost. Pedestrian light Architectural Area Light’s ‘Universe’ Medium, with ‘Skirted Bell Hood’ Catalog number: SLBBL22H3-PR55R18-250 00A-1117 Customized pole with bracket arms Finish: polyester powder coat chromate primer Color: Black grey RAL#7021 Lamp type: LED FCO, Full Cut off Shield Roadway light Architectural Area Light’s ‘Flex Fixture’ or similar. With long straight arm Lamp type: LED ENHANCED ELECTRICAL CAPACITY In an effort to improve the festival and event experience for the vendors, enhanced electrical capacity is needed along Iowa Avenue and Clinton. Options for increased power distribution have been identified. Illumination recommendations Roadway and intersection lighting recommendations are charted. All study area streets are classified as ‘collector’ roads. STREETSCAPE COMPONENTS | LIGHTING + ELECTRICAL FEBRUARY 2014 43 LIGHT ART AT ALLEYS ENHANCED ELECTRICAL CAPACITY ARCHITECTURAL LIGHTING / LIGHT OPPORTUNITY LED PEDESTRIAN / ROADWAY LIGHTS THROUGHOUT STUDY AREA IDENTITY LIGHTING AT MARKET STREET MONUMENT PEDESTRIAN ROADWAY LIGHT BANNER PROGRAM, PEDESTRIAN LIGHTING ENHANCED STOREFRONT LIGHTING ACCENT LIGHTING AT SELECT PED MALL TREES STREETSCAPE COMPONENTS | LIGHTING + ELECTRICAL IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 44 LIGHTING STREET-BY-STREET The following shows which lighting components are rec- ommended on each street. MARKET STREET NORTH SIDE MARKET PLACE NORTH LINN STREET BLOOMINGTON STREET STREETSCAPE COMPONENTS | LIGHTING + ELECTRICAL Existing Existing FEBRUARY 2014 45 BURLINGTON STREETMonumental limestone base at inter-sections only. CLINTON STREET COLLEGE STREET STREETSCAPE COMPONENTS | LIGHTING + ELECTRICAL IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 46 GILBERT STREET IOWA AVENUE STREETSCAPE COMPONENTS | LIGHTING + ELECTRICAL WASHINGTON STREET FEBRUARY 2014 47 LINN STREET STREETSCAPE COMPONENTS | LIGHTING + ELECTRICAL DUBUQUE STREET IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 48 STREETSCAPE COMPONENTS |GREEN INFRASTRUCTURE | PERMEABLE PAVEMENT PERMEABLE PAVEMENT A permeable paving system is proposed along Wash- ington, at Black Hawk Mini Park, and at the center alley section to collect, cleanse, slow and filter storm water. In terms of overall runoff reduction volumes, it can conserva- tively be assumed that a porous pavement street will ab- sorb 0.5” of rainfall even if no infiltration occurs under the permeable paving. If we assume that 33% of the annual rainfall events generate less than 0.5 inches of precipita- tion over a 24 hour period, and that annual average rain- fall is 36”, then permeable paving can directly absorb 12” per year of direct rainfall with no runoff whatsoever. This would translate into 7.5 gallons absorbed per square foot of pavement per year for pavement that receives direct rainfall. For many streets where permeable paving is installed, a conventional storm sewer will not be needed provided that only the ROW of the project area drains to the per- meable paving. Where additional areas such as upstream streets and/or adjacent properties drain onto the project area, storm sewer or additional gravel storage may be needed to accommodate the additional runoff, depend- ing on the amount of additional area relative to the proj- ect area. Typically, the street will only need to incorporate a 4” drain tile, depending on the size of the project. The tile should tie into existing storm sewers or other suitable outlet. Typically, permeable paving will reduce the peak flow by over 90% for the ROW and therefore potentially eliminate the need to replace downstream undersized storm sew- ers, depending on how undersized and how much of the drainage area is addressed. If the drainage area includes much more than just the ROW, the peak flow reduction will be less, depending on the ratio of drainage area to permeable paving area. Permeable pavements are typically less subject to freeze thaw than standard pavements due to the nature of the open graded stone of the pavement base and due to the level of drainage of the base. Even in standard imper- meable pavements, water can enter the pavement base due to cracks in the pavement surface. Due to the fines in standard pavement base, some water is retained in the voids and that water is subject to freezing. Further, drain- age is rarely provided in the base of standard pavements, which can result in extended periods of ponding in the base, which is also subject to freezing. The frozen water in the base of the standard pavement can lead to frost heave of the pavement surface and formation of cracks and potholes, which in turn leads to greater volumes of water entry into a pavement base not designed to man- age water. Because permeable paving has drainage and is designed to manage water, it is much less subject to freezing and frost heave. While all pavements are subject to snow accumulation and resulting slick conditions, the permeable nature of the surface of permeable paving results in greatly reduced re- freezing of melt water and formation of black ice. A study at the University of New Hampshire Stormwater Center evaluated the use of porous asphalt as a source control measure for chlorides. They found that “the lack of stand- ing water on the pervious pavement surface greatly re- duces the frequency and mass of salt applications need- ed during winter precipitation or freeze-thaw periods.” The study reports that annual snow and ice cover was three times greater on the conventional pavement than the pervious pavement. This resulted in an over 75% reduction in annual salt usage for the permeable paving. Modular permeable paving systems (permeable pavers) can be removed and replaced, creating much less con- spicuous patches when pavement is removed to repair utilities or the pavement itself. Finally, a properly designed permeable paver system should last up to 50 years, 2 to 3 times the life of a conven- tional asphalt pavement and does not require seal coat- ing on a regular basis. Summary of Permeable Paving Benefits • Reduces the rate and quantity of stormwater runoff, reducing the load on downstream storm systems • Virtually eliminates nuisance ponding on the pavement surface due to potholes or flat areas of pavement • Can reduce winter salt usage, saving money as well as reducing chloride impacts to downstream water resources • Filters and retains typical urban pollutants associated with streets, including sediment, heavy metals, and or- ganic hydrocarbons. • Extended service life of the pavement (permeable pavers). Maintenance Considerations: • Depending on choice of pavers, some litter and debris may collect in the openings. • Pavements subject to high levels of sediment loading due to construction or adjacent poorly maintained landscape areas may experience localized clogging of the pavement surface that will necessitate clean- ing to restore permeability. • To prevent scratching and minor chipping of paver surfaces, the community may want to utilize nylon rather than steel edging for their snow plows and/or use blade shoes to hold the blade slightly above the pavements surface. • The initial cost of permeable pavement may be higher than conventional paving depending on the scope of the project. Implementation of a permeable paving system will always be higher than a mill and overlay project. However for a full depth removal project that may also involve upsizing of storm sewer under a con- ventional paving project, the permeable paving sys- tem may be less expensive due to the avoided cost of storm sewer replacement. FEBRUARY 2014 49 BIORETENTION PLANTING AREAS Bioretention planting areas are proposed along select streets to enhance rain water infiltration, minimize runoff, slow peak flows and remove pollutants. As depicted in the adjacent images, runoff is directed into the bioreten- tion area, which utilizes both soils and plant material to remove pollutants from the storm water runoff. The bio- retention area is graded to the center and water slowly infiltrates and/or filters and discharges the treated water. Underdrains may be included depending on soils and size of drainage area. Further analyses is required in subse- quent design phases to understand underlying soils, exist- ing slopes along the streetscape, location of utilities, and health of existing trees located near proposed bioreten- tion planting areas. Bioretention provides storm water treatment that enhanc- es the quality of downstream water bodies. The Environ- mental Protection Agency estimates that bioretention planting areas can remove 90-percent of metals, between 68 and 80-percent of TKN and between 70 and 83-percent of total phosphorus. When designed and built appropri- ately, bioretention areas can potentially achieve greater than 90-percent removal rates for total suspended solids, organics and bacteria. STREETSCAPE COMPONENTS |GREEN INFRASTRUCTURE | BIORETENTION PLANTING AREAS Bioretention planting areas are proposed along Market, Washington, College, and Dubuque. The bioretention planting areas will collect, cleanse, slow, and infiltrate storm water. IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 50 STREETSCAPE COMPONENTS |GREEN INFRASTRUCTURE | GREEN ALLEYS GREEN ALLEY PROGRAM The existing alleys are underutilized, under illuminated, and most of the alley paving is uneven and in a state of dis- repair. Considering the visual impacts of the alleys to the larger context, there are tremendous opportunities to bet- ter integrate the alleys with the downtown and to demon- strate the City’s commitment to sustainable infrastructure by installing permeable pavement systems at the alleys. Other measures recommended as part of the ‘green alley’ program. • Consider policy changes to consolidate the dump- sters. • Add LED lighting for an improved sense of safety. • Celebrate the work of local artists with revolving ‘al- ley art’ shows. Feature local muralists, light artists and graphic designers. • Utilize the alleys as flexible programming space. Permeable paving in alleys Permeable paving at the center section of an alley in Chicago Example of temporary art installation Temporary art installations activate the alleys and feature the work of local artists Alleys as flexible space Utilize the alleys for performances and as flexible space OTHER GREEN INFRASTRUCTURE STRATEGIESReduction in energy usage• Convert the existing street and Ped Mall lighting system to LED. Possible total estimated energy reduction in the Ped Mall alone approximates 55%. Refer to lighting and electrical, in this section. • Equip the proposed sheltered bicycle parking canopies with solar panels for improved safety and illumination. Waste reduction• Enhanced recycling opportunities: four new recycling stations are proposed throughout the Ped Mall. Refer to “sustainability” in the pedestrian mall planning | plan-ning framework section. Education and outreach• An EcoLAB is proposed in the Ped Mall and is organized around themes of renewable energy, the cycle of wa-ter, recycling, urban gardening, and local food. Refer to “Play” in the pedestrian mall planning |planning frame-work section. Transportation choices• Enhanced crosswalk paving improves walkability and the sense of pedestrian safety. • Enhanced bicycle accommodations are proposed along Market, Clinton and Gilbert. Six new locations for covered bicycle parking areas have been identified. Refer to transportation enhancements, this section. FEBRUARY 2014 51 STREETSCAPE COMPONENTS | GREEN INFRASTRUCTURE BIORETENTION PLANTING AREA OPTION ENHANCED CROSSWALK PAVING PRO-MOTES WALKABILITY SHELTERED BIKE PARKING EQUIPPED WITH SOLAR PANELS CONVERT EXISTING LIGHTING TO LED PERMEABLE PAVEMENT OPTION ENHANCED BICYCLE ACCOMMODATIONS(DESIGNATED AND SHARED BICYCLE LANES) IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 52 AUTO Transportation enhancements are proposed along Clin- ton, Gilbert, Market, and Burlington. The enhancements are varied and include a reduction in the number of travel lanes, conversion to two-way traffic, or enhanced cen- ter turn lane paving. A reduction in the number of travel lanes, or a ‘road diet,’ is proposed along Gilbert and Clin- ton Street. The number of travel lanes is reduced to afford space for on-street designated bicycle lanes. (The feasibil- ity of potential road diets and bicycle lanes must be con- firmed following a traffic study based on traffic patterns and site conditions.) The proposed Clinton Street section includes two north- bound travel lanes, one southbound travel lane with par- allel parking on both sides of the street. As another option, one northbound travel lane and two southbound travel lanes could be considered. A traffic study is needed to de- termine the feasibility of the reduction in travel lanes. Bus queuing is relocated to Washington. The reduction in trav- el lanes also affords an additional 6’ to be re-allocated to the easterly sidewalk, which is currently a very congested pedestrian environment. A conversion to two-way traffic is proposed along Market Street. The street section is also re-striped to accommo- date on-street bicycle lanes. Parallel parking along the north side of the street is maintained. Enhanced center turn lane paving is proposed along Bur-lington Street. The proposed Gilbert Street section includes one travel lane in each direction with a center turn lane. On-street designated bicycle lanes are proposed. CLINTON STREET MARKET STREET BURLINGTON STREET GILBERT STREET STREETSCAPE COMPONENTS | TRANSPORTATION ENHANCEMENTS | AUTO FEBRUARY 2014 53 BUS There was minimal stakeholder discussion or public input surrounding bus transit within the study area. Therefore, the current plan does not recommend any changes to the ex- isting bus routes or the ten bus stops. The following recom- mendations address bus queuing and pedestrian-related enhancements at the bus stops. • The proposed planning concept for Clinton Street pro- poses a relocation of the bus queuing from Clinton Street to Washington Street. • As feasible, consider solar panel-covered bus stop can- opies for illumination. WALKABILITY Per the ICDD, the City of Iowa City has the highest walk- ability ranking in the state of Iowa. Downtown Iowa City has earned a “Walker’s Paradise: Daily Errands Do Not Re- quire a Car” 95/100 score on the popular walkability Walk Score website. The measurement considers how many businesses, parks, theaters, schools and other common destinations are within walking distance of any given start- ing point. Walkable communities provide countless ben- efits to people’s health, the environment, the economy with reduced commuting costs as an example, and to the larger sense of community. Existing crosswalks will be enhanced in order to create the walkable, pedestrian-oriented environment that is envisioned for downtown. Enhanced crosswalks, either unit pavers or painted designations, are recommended throughout the study area. ADA-compliant curb ramps with tactile warning strips are currently limited and need to be upgraded as part of all future improvement projects. STREETSCAPE COMPONENTS | TRANSPORTATION ENHANCEMENTS | WALKABILITY AND BUS Painted crosswalk designations are proposed at Blooming- ton /North Linn. Unit pavers at the crosswalks are proposed along Market Street, and at select intersections along Burlington, at Gil-bert / College, Dubuque / Washington. In nearly all instances, curb ramps need to be updated to conform to the most recent standards published in accor-dance with the Americans with Disabilities Act. Cast Iron textured curb ramp panels are recommended. IMPROVED CROSSWALKS ENHANCED CROSSWALK PAVING ADA-COMPLIANT CURB RAMPS IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 54 BICYCLE ENHANCEMENTSEnhanced bicycle accommodations have been integrat-ed into the streetscape planning concepts in order to pro-mote a variety of mobility options across the study area. Enhancements include on-street designated bicycle lanes and six new locations for sheltered bicycle parking. Plan-ning recommendations follow. • Designated bicycle lanes are proposed along Clinton, Gilbert and Market Street. (The feasibility of potential bi-cycle lanes must be confirmed following a traffic study based on traffic patterns and site conditions.) • Equip new bicycle parking shelters with solar panels for improved safety and illumination. • Replace the existing corroding bicycle racks along the sidewalk with new racks. Specific locations and quanti-ties will be identified during subsequent design phases. The recommended replacement rack: ‘Bola’ by Land-scape Forms, black powder coat, standard inverted ‘u’ rack. On-street bicycle lanes Paint on-street bicycle lanes with a bright, solid color. This delivers a strong message that bicyclist safety is a priority Proposed bicycle accommodations STREETSCAPE COMPONENTS | TRANSPORTATION ENHANCEMENTS | BICYCLE FEBRUARY 2014 55 TRANSPORTATION AND PEDESTRIAN SAFETY ENHANCEMENTS STREETSCAPE COMPONENTS | TRANSPORTATION ENHANCEMENTS NEW PAINTED CROSSWALKS PEDESTRIAN REFUGE EXISTING UNIT PAVER CROSSWALKS CONVERSION TO TWO-WAY TRAVEL TRAVEL LANE REDUCTION ENHANCED CENTER TURN LANE EXISTING UNIT PAVER CROSSWALKSNEW UNIT PAVER CROSSWALKS ENHANCED ADA RAMPS THROUGHOUTBICYCLE ACCOMMODATIONS ON P 54 IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 56 SUCCESSIVE PLANTINGS Upon completion of the arborists review of the existing tree palette, the following recommendations apply to any suc- cessive plantings. • Infill plantings and tree selections by street. Following review of the existing tree palette by a certified ar- borist, the planning team recommends that an ‘ap- proved tree species list’ be created for each street. As existing trees die or are removed, they should be replaced by the chosen tree(s) for the street. The tree selection process will consider local performance, dis- ease resistance, canopy size, overall shape and form, leaf shape and color, ability to grow within confined areas (overhead utilities, facades, and limited root zones), snow removal, microclimate, lighting, parking, underground sewers and vaults, and typical root char- acter. • Tree diversity. There are aesthetic advantages to planting a single tree species or cultivars along a streetscape and great impact can be achieved. But lessons learned with monoculture planting, the Amer- ican elms as an example, are reminders that tree di- versity is “a community’s best hedge against potential disaster”. Per Iowa State University Extension, for max- imum protection against insects, disease, or environ- mental stress, the urban tree population should reflect: No more than 10% of any single tree species. No more than 20% of species in any tree genus. No more than 30% of species in any tree family.• Thinning and pruning of high value trees. Street trees should offer a rich canopy that covers the majority of the sidewalk and extends into the street. Shade should be offered, but it should not be so thick as to prevent filtered sunshine or to allow the sun to pass through to the street during the winter months. Thinning and prun- ing of those trees ranked ‘high value’ by the arborist is recommended. • Linear planting trench. Where the existing conditions prohibit the minimum planting pit, alternative planting solutions may be considered such as linear tree plant- ing trenches with removable pavers. As an example, to maximize the hardscape areas of Washington, Dubuque, and Linn while providing the best possible environment for street trees, a paver grate system and continuous planter trough is recommended for tree plantings. The system, similar to the system manufac- tured by Ironsmith, uses a hidden metal grate to sus- pend pavers over the tree’s planting zone, reducing soil compaction and opening up wide areas for pe- destrian movement in tight areas. • Continuous planting trench. On streets with more space for pedestrian movement such as Clinton, Gil- bert, and College, open, continuous tree trench with understory perennial planting or lawn is recommend- ed. The continuous tree trench may be broken peri- odically with pavers to allow access to parking and amenity zone items like benches, bike racks, etc. EVALUATIONThe existing tree canopy plays a key role in contributing to the overall character of Downtown. Found on most every street, the trees are valued for their shade, scale and char-acter. They announce the changing seasons, create com-fortable shade, and they greatly improve the walkability of the environs. As an example, the consistent planting of Ash and Honey Locust trees along Iowa Avenue creates a memorable and unique identity unique to that streets-cape. There was minimal public or stakeholder input on the ex-isting tree plantings. A general analysis of the existing tree palette found many of the trees are of questionable health, most likely due to the basic fact that urban areas are not tree friendly. Many of the trees planted in an urban environment struggle due to a variety of factors including soil compaction, low soil fertility, inadequate moisture, air pollution, pet urine, and detrimental de-icing salts. Addi-tionally, in tree pits such as those found across the study area, trees have a limited lifespan. At the onset of the next design phase, the planning team recommends the City hire a certified arborist to do an inventory and analysis of the existing trees. Factors to consider when evaluating the existing trees include a tree’s age, health, size, species, overall form, and planting location as it relates to future development. Existing Columnar maples along Burlington STREETSCAPE COMPONENTS | LANDSCAPE & PLANT MATERIAL Existing Honey Locust and Ash along Iowa Avenue FEBRUARY 2014 57 • Proposed Street Tree Size. Infill trees to be canopy trees that will provide shade, but are limbed high enough to prevent obstruction of views of passing motorists and allow for safe pedestrian passage along sidewalks. To minimize conflicts of lower tree limbs with vehicular and pedestrian zones, bottom tree branches shall be at least 8’ above adjacent sidewalk grade at the time of tree planting. All new street trees shall be a minimum 2” caliper size (the diameter of the trunk measured one foot above grade) at the time of tree installation. • Infill tree standards. All future street trees must meet the requirements of the American Standard for Nurs- ery Stock (latest edition), as published by the Ameri- can Association of Nurserymen. • Proposed Street Tree Placement. Where there are significant gaps in the existing tree planting pro- gram, along Gilbert, Burlington, and Bloomington as examples, or when full streetscape and sidewalk im- provements are implemented, new tree spacing will respond to street light locations which, in turn, relate to locations of on-street parking spaces. • Ash Tree Blight. All varieties of ash trees are at risk of the disease spread by a beetle called the em- erald ash borer. Experts from the U.S. and Iowa departments of agriculture, Iowa Department of Natural Resources, and Iowa State University have confirmed there are ash trees infested with the em- erald ash borers in eastern Iowa counties and ‘the problem is spreading faster than originally thought’. Implementation of a strategy to combat the spread is recommended and should begin with a detailed inventory of ash trees within the study area. Any ash trees that are already in a state of decline may need to be removed sooner rather than later. As an example, there are a number of mature ash trees along Washington. The possibility of their removal will have a significant impact on the streetscape char- acter and the further development of the streets- cape plans for Washington. Freeman Maple Ginkgo Honey LocustPrinceton Elm STREETSCAPE COMPONENTS | LANDSCAPE & PLANT MATERIAL IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 58 UNDERSTORY PLANTINGS At-grade landscaping in planters is a key component of greening and softening the streetscapes. Plantings along the sidewalk buffer pedestrians from traffic and parked cars and provide a memorable visual impact to the street. The understory plantings are visualized as multi-dimensional with shrub, ornamental grass, ground- cover, and seasonal plantings. The proposed palette can be replicated throughout the study area to unify and provide meaningful visual impact. • Irrigation. To reduce City maintenance requirements and to ensure healthy tree growth, irrigation at new planting areas is recommended where full streets- cape improvements are proposed. System specifics and feasibility across each of the individual streets will be considered during subsequent design phases. RECOMMENDED BIORETENTION PALETTE A combination of drought tolerant, hybrid ornamentals and a few natives is recommended for the bioretention planting areas. Examples of recommended plants fol- low. The palette will be refined during subsequent de- sign phases. • New England Aster Hybrids • Native Sedges • Northern Prairie Dropseed • Little Blue Stem • Native and Hybrid Penstemons (NOTE: the plants listed are a sampling of potential choices and that a more thorough plant list will be developed for each unique application during the detailed design and implemen- tation phases of the project) Little Bluestem New England Aster HybridNative Penstemon Native Prairie Dropseed STREETSCAPE COMPONENTS | LANDSCAPE & PLANT MATERIAL FEBRUARY 2014 59 WHAT PUBLIC ART MEANS TO IOWA CITYIowa City’s public art program makes the city a more memorable place to live, work and visit. The broad range of public artworks seen across the City elevates the quality of the public spaces and reinforces Iowa City’s reputation as a center for the arts, culture, and literature. The majority of the artwork celebrates Iowa City’s unique literary history. Per the City of Iowa City public art program, ‘From acclaimed poets and playwrights, to accomplished novelists and journalists, Iowa City has been both host and home to literary genius’. As a result, Iowa City is one of six designated Cities of Literature by the United Nations Edu-cational, Scientific & Cultural Organization (UNESCO) and the only community with such designation in the United States. To recognize the literary history, Iowa Avenue’s ‘Lit-erary Walk’ celebrates the works of 49 writers with ties to Iowa and is comprised of a series of bronze relief panels that feature literary quotes and attribution. It is the intent of the current plan to support the existing public art program and to build on that success with new public art opportunities. STREETSCAPE COMPONENTS | PUBLIC ART Literary walk The ‘Literary Walk’ bronze panels were in-stalled in 2000 and unfortunately some of the panels are beginning to lift. Explore incorporation of the panels into the new light pole bases proposed along Iowa Av-enue or other downtown locations. Public art piece along Iowa Ave Illuminate select artworks to highlight and add drama at night Alley art An ‘alley art’ program celebrates the his-tory of murals in Iowa City and showcases the work of local artists Murals Murals and oversized banners are pro- posed to activate the blank parking ramps along Burlington Northside Market Place public art Include new literary - themed public art-work along North Linn IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 60 SIDEWALK PAVING A consistent sidewalk pattern that will allow the ground plane to read as one continuous public space and not a series of spaces associated with individual streets is recommended. This will allow the public artwork, veg- etation, and other furnishings to become the focus for the street. • PCC paving is the recommended sidewalk paving material due to its durability as well as its ease of maintenance and replacement. The PCC paving recommendations include a standard grey color with 50% sandblast finish, 50% broom finish, and saw cut control joints. • Along select streets, the proposed sidewalk paving includes a combination of PCC paving at the pri- mary walkway along the buildings and unit pavers along the curb zone. The proposed unit paver colors will include a range of grey colors and will appear ‘speckled’ in an attempt to minimize the impacts of spills and stains typical to urban settings. The recom- mended unit paver size is 12” x 18” or smaller. STREETSCAPE COMPONENTS | KIT OF PARTS PCC paving is proposed along the side-walks STREET PAVING The majority of the streets throughout the study area have been paved with either concrete or bituminous concrete. Unit pavers have been installed along Iowa Avenue between Clinton and Dubuque and to highlight significant intersections along Clinton. Street pavement conditions vary. Replacement recommendations are tied to infrastructure improvement projects as feasible. Replacement recommendations follow • There have been concerns with the pavement con- ditions along Washington and there was a 12-inch water main break along the 100 block of Washing- ton. Concrete paving is proposed as the replace- ment paving material at the street with permeable pavement as an alternate. • To extend the character of the Ped Mall north to Iowa Avenue, unit pavers are proposed along Dubuque Street. • To break up the expanse of paving across Burling- ton, unit pavers are proposed to distinguish the cen- ter turn lane. (The most recent paving improvements along Burlington were in 1984.) • The existing street paving along College, between Linn and Gilbert is of concern. Concrete is the rec- ommended replacement material. Paver ‘speckling’ helps minimize impacts of stains and spills Unit pavers are proposed along Dubuque St. To break up the expanse of paving across Burlington, unit pavers are proposed to distinguish the center turn lane. (The most recent paving improvements along Burl-ington were in 1984.) FEBRUARY 2014 61 STREETSCAPE COMPONENTS | KIT OF PARTS TRASH AND RECYCLING Trash receptacles are easily found throughout the study area. Their character complements the metal strap benches and seems similar to the Landscape Forms’ ‘Scarborough’ receptacle. Recycling stations are cur- rently limited to the pedestrian mall and public input in- dicates a strong desire for recycling containers/stations throughout downtown. The Plan offers two recycling container options: the ‘Scarborough’ receptacle which matches the existing trash containers and the ‘Big Belly’ compactor. Prior to making a final selection, further coordination is needed with the City representatives to understand pick-up and sorting options. Replacement containers are recommended for the ex- posed aggregate/metal top trash receptacles currently found at the Northside Marketplace. SEATING Benches are an important component of a pedestri- an friendly streetscape and are generally abundant throughout the study area. The exception is the streets- cape along South Linn between the Sr. Center and the Iowa City Public Library. Most of the benches are hori- zontal metal strap and share a similar style to Landscape Forms’ ‘Scarborough’ bench. Most are in good condi- tion. The ICCD Community Gallery BenchMarks bench- es have been installed at select Northside Marketplace locations. Each year, the benches are treated as blank canvasses and are re-painted to feature the work of lo- cal artists. Seating recommendations follow. • Consider the metal strap bench as the standard bench for downtown. • Install benches along Linn, between the Sr. Center and ICPL. • Center arms to be included in new benches 72” in length or longer. Existing Bench Along Washington Street ‘Scarborough’ trash receptacle. Color: Black Big Belly’ recycling compactor. Cordless self powered unit. Color: Black.Recommended metal strap bench. Color: Black. Center arm detail shown for those benches 72” in length or lon-ger. STREETSCAPE COMPONENTS | KIT OF PARTS IOWA CITY DOWNTOWN AND PEDESTRIAN MALL STREETSCAPE PLAN UPDATE . DRAFT P | 62 STREETSCAPE COMPONENTS | KIT OF PARTS BICYCLE FURNISHINGS Six locations for enhanced bicycle accommodations have been identified. Locations were mapped within the transportation section. The planning team recom- mends the shelters be equipped with solar panels for safe illumination at night. Many of the existing racks are corroding and further detailed analysis of each rack is recommended during subsequent design phases for each of the individual streetscapes. The standard inverted ‘u’ bicycle rack is proposed as the replacement rack across the study area. The ‘BOLA’ rack by Landscape Forms as shown above represents the desired character. PLANTING CONTAINERS Enrichment of the pedestrian environment is important to a successful street and small details can do big things. Along the more heavily paved streets like Dubuque, Washington, and Linn, the introduction of planter pots will help add seasonal color to the more urban environ- ments of Iowa City. Pots should be large enough to be effective, roughly 30” high and 48” in diameter, made of integrally colored precast concrete to match existing and proposed limestone material downtown. Like planter pots, hanging baskets on light poles ad sea- sonal color and are a small, effective detail to enhance the pedestrian environment. The lighting design incor- porates hanging baskets on Dubuque’s monumental light column. This adds that extra level of enhancement while leaving more surface pedestrian space open. Installing an irrigation system to the containers and hang- ing baskets is recommended and will be determined on a street-by-street bases dependent on the level of im- provements proposed at each street. Colorful, cascad- ing plants are proposed and may include Bacopa, Cal- ibrachoa, Lantana, Verbena, Ivy Geranium, and Trailing Petunia. Planter Pots. Style is to be similar to the “Biltmore” by Dura Art Stone. Bicycle shelter equipped with solar panelsHanging baskets with colorful, cascading plantings are proposed along Dubuque Street. The baskets are sized at 18”-24” Landscape Forms, Bola bicycle rackColor: Black powdercoat 1 ½” Schedule 40 Pipe, 36” h x 18” w FEBRUARY 2014 63 [ PAGE INTENTIONALLY LEFT BLANK ]