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5 - Matters from the Board, Review and Feedback on the Broadway Reconstruction Project Preliminary DCity of Boulder TransaortatiQn P.O. Box 791 B0t11dEr. C(} 8(13(ll ~a... Ms. Georgia 7ackson Cilv Of Bonlder Parka De~i PO Box 791 Boulder CO 803060791 11.~1~11~.~~~11~11~.~~11~~11~..1~~~11~1~~~~.111~1~~~~~11,11~~1 Presorted Frst-Class Moil U S Postage PAID Boulder, CO PermitNO 909 Broadway Reconstruction Project . .: ,. ~ PR~t11VliNARY D~ESI G N CO1VlPt~ET~ED n impartant milestone m the design of the Broadway ReconStrucTion Pra~ect was achieved on August 30ih whe~ A The City of Boulder Transportahon Drvision submiNed pre6minary engineenng drawings to the Colorado DepaRment of Transporfation (COOT) At ihe same time, a checklist of anticipated impacts and descnption of impact mitigation for ihe preliminary design was submitted for The citys Community and Environmental Assessment Process (CEAP~. The preliminary design drawings include reconstruction of Broadway between University Avenue and Pine Sireet and sidewalk and sheetscape enhancements Several bndge rehabilitaTion and reconstruction opTions were evaluated dunng preliminary design and analysis The result of ihis analysis was ihe recommendation included in the CEAP to replace the ewshng bndge with a new structure iwo pnmary bndge configuralions were induded in the CEAP, a rivo-span ophon, and a single span option Additional evaluation of these iwo replacement options was completed following the submittal of the CEAP, including review by the Colorado Deparfment of Transporfation This led to a recommendation fo consiruct a new single span, ,.~--, slightly arched concrete girder bndge to replace the existing two-span bndge The bndge design includes increased ~, siructural capacity/safety and floodway conveyance, improved pedestnan and bicycle safeiy on the Boulder Creek path, and maintenance af imgation ditches fie bndge design incorporates design elemenis of the history of the present bndge in the Ciwc Center Preliminary Design lncorporates ideas from the Public Open Houses and Stakehoider Meetings Public commenT dunng early pro~ecT planning and design has been an essential elemeni in the development of ihe preliminary engineenng drawings Several opportunities for public input have been provided, and many good ideas and concepis for improvmg the design have been obtained ~, On July 13th, city agency stakeholders met wiTh pro~ect designers and made specific ~ recommendations regarding improved safey, maintenance and preferences for design concepis presented On July 24th, ihe second public open house meeTing allowed utizens to talk directly with pro~ect designers about Their specific issues and concems These focussed pnmanly on dunng- co~struchon impacts to haffic, ad~acent ne~ghborhoods, and pedestnan and bicycle safety Dunng July and AugusT, meetings were held vnth aty advisory boards and vanous neighborhood and interest groups requeshng additional pro~ect information All of the inpui recerved has been included in ihe CEAP Additional aty advisory board meetings will continue over the nexT couple of monThs Please see ihe pro~ect web site at www bouldertransportaTion net for meeting dates SecondoP~rrouse Bridge and Floodway Design Affer studying both rehabilitation and replacement opiions for the Broadway Bndge over Boulder Creek, it is recommended that ihe bndge be replaced with a new siructure The preliminary design recommends a s~ngle span configuraTion with a classic arching shucture The CEAP includes both one and Two span (similar to ihe ewshng bndge) configurations. Rehabditahon of the ewsting bndge would be exiremely difficult and cosTly There is a high degree of uncertainty wheTher the important architectural features of the bndge would survrve rehabilitation efforis due to their fragile condition (particularly the bndge fasaa and bridge rail) Safety improvemenis necessary to meet present standards would adversely affect ihe histoncal integnty of the bndge Rehabilitation would not allow for easily increasing the flood carrying capaafy with the current pro~ect or if other floodway improvemenTs are made in the future The new bndge design will not require modification to the ditch headgate locoted in Cenhal Park ~ The use of modem matenals and construction techniques will allow a new single span structure with a slender and sleek `° design to span the creek with no supporting columns required. fie clear span will allow visitors to Ceniral Park to view both sides of ihe park This will improve ihe visual connection at the park and provide a positrve visual expenence 7he bndge will be classically arched similar to the existing bndge and similar in the design of ihe piers, abutments, pedestnan railing, and lighting pedestals and fixtures Access to ihe Bo~lder Creek path will be improved with a 22-foot wide path under ihe bndge The improved hydraulic performance of the bndge will mitigate paTh closure dunng high spring run-off and other storm evenTs The new bndge design will accommodate ihe following pro~ect goals • Meei cunent bndge design siructural and safety standards • Improve the flood cartying capaaty under Broadway ~ 9ngle span slightly arched bndge across BoultlerCreek ond BoulderCreek Path • Can be exoanded to accommodate future flood improvemenis to the creek ^ BroadwayStreetimprovements Concrete pavement will be utilized for the street reconsTrucTion to better accommodate ihe high vehicular and bus fraffic volumes, while miniminng fhe overall lif~cycle cosis of pavement maintenance Reconsiruction wdl also improve ewsTmg drainage inleis and include improvemen}s to ihe storm sewer system between Manne and Arapahoe and belween Walnut Street and Boulder Creek These upgrades are part of the c~iy's Stortnwater Collection System Master ~^ Pian ~ The reconstructed povemeM section wdl mamtain histoncal lane widihs, thereby eliminahng encroachment into ex~sting sidewalks and impact To adjacent sfreet frees Maintaming the histonc lane Nndths will, however, require vanance from CDOT and FHWA design standards The use of concrete will not change future noise levels compared to ewsting noise conditions Slight roadway profile ad~ustmenTs (one foot or less) will be made behveen University and Manne to expedite conshuction through ihe comdor by recycling the ex~sTing pavemenT in place, Thus eliminating the need to excavate the ewsting roadway. This will enable a better match with ihe profile of ihe existing sidewalks. Between Canyon and Arapahae, the profile v.nll be similarly raised to increase ihe hydraufic opening for the bndge over Boulder Creek The roadway cross-slopes will be Flattened to provide ADA campliance for cross slopes Sidewalks and curb access ramps will be improved in many areas. Auto, Transit & Pedestrian lmpacts Dunng constn~ction, two Shrough lones (one m each dvection) v~nll be mainTamed. Left-turn lanes at The ma~onty of the pnmary signalized intersections wiil be maintained, although they may be shoRer than ewshng and some temporary ~off- peak or nightt~me) lane closures or tum resfictions will occur. Elecfronic message signs at fhe northem and southem eniryway points to the aty v.nll be insialled to recommend travelers To take altematrve routes such as 28th Street or Foothtlls Parkway IT is anhcipated That some fraffic wili divert to parallel sfreets, alThough these local sheets will nof be suggested as altemative routes. Coardination is underway with RTD to ensure that ewsting bus services will be maintamed dunng consirucTion Some regional and local bus routes may be rerouted to avoid congesTion along this sfretch of Broadway fie SKIP route will remain along The pro~ect length Pedestnan and bicycle access will also be mainTained through ihe length of the pro~ect ~ Sidewalk and Streetscape Enhancements ~, Overall enhancements v,nll include concrete sidewalk repair and replacement, continuous street free planting, consistenf and identifiable bus stops, accent plantings at key locations, and use of bnck and stone as accent maTenals In the Hill area, ihe charactenstic free lawns will be maintained and transitional landscaped medians provided south of Arapahoe In the Crvic Center, the formal crvic setting of 'he govemment buddings and ihe park will be enhanced wdh pedestnan and landscape improvements in ihe downtown areo, sidewalk improvements and pedesTnan amen~ties will reflect ihe histonc character of downtown and elements of ihe Pearl Street Mall The sidewalk and sireetscape enhancements focus on improvements at three lypical locations along Broadway comers and gateways, curbside nght-of-way, and fransit and avic places. Some of these ultimate streetscape improved may be phased as paR of future improvements due to budgeting consframts ~ . --, Historical Resources Environmental Assessment Dunng ihe pro~ect, eight different bndge altematrves were evaluated as required for ihe Section 106 review of the Nafional Histonc Preservat~on Act ~NHPA) and Seciion 4(f) of the Department of Transportation Act of 1966 fie reconshuction of ihe Broadway Bndge will cause adverse impacts to the ewsting bndge, which is considered to be eligible for I~sting on ihe Nat~onal Register of Histonc Places Adverse effech detertnined by the State Histonc Preservahon Office (SHPO) may also occur for the holley hacks ihat are buned under Broadway At This fime, preliminary field assessment is that the impacT to ihe trolley tracks vnll not be adverse No addihonal adverse impacts are expecied to occur to any oTher histonc structures or properfies Archaeological assessments are undervvay by The Colorodo Department of Transportahon (CDOT) Dunng ihe planning and preliminary design process, staff and consultanis met with ihe City of Boulder Landmarks Preservahon Advisory Board ~LPABJ at iheir May, June, and Juy meehngs To obtain their input on The bndge altematives and histonc analysis This input is included in ihe CEAP Q ~n Howe What's Neact Affer the CDOT review of tFie preliminary design drawings and The cilys review through the CEAP, preparahon of final design conshuction drawings will begin It is anhcipated this final design phase of the pro~ect vnll take approwmately 1wo months Through the CEAP process, the design is submitted to the City's Development Review Committee which recommends the pro~ect for review and comment by selected ciiy advisory boards fror the Broadway Reconstruction Pro~ect, ihese will include the landmark Preservafion Advisory Board (LPAB~, the Greenways Advisory Committee, the Downtown Design Advisory Board (DDAB~, and the Parks and Recreafion Advisory Board ~PRAB) fie Transportahon Advisory Board ~TAB) will consider ihe recommendations of the other advisory boards and make a pro~ect recommendat~on to City Counal With Council approval, final design and conshuction can begin There are no ma~or natural environmental effects anticipated from the pro~ect Impacts will occur pnmanly dunng consTruction and be of short-term duration, including• s~ • Increased sedimentation inio Boulder Creek The proJect .,,~ will use Best Management Practices to I~mit sedimentation An Erosion Control Plan will be developed to protect water quality in the creek • Some }emporary detenoration in air quality will occur due to surface disturbance The site will be regularly watered to minimize dust • Use of heavy construction equipment will result in temporary noise impacts, but ihe contractor will be required to meet aty code requirements • New medians and additional curb-side imgation will slightly increase water usage The pro~ect will use a dnp system where possible to minimize ihe increase in water usage We are here Fnal, design drawings for ihe Broadway ReconshucTion Pro~ect will be available for public viewing in the lobby of the Municipal Building once ihey are completed Press and electronic media, ihe pro~ect Web site, and pro~ect newsletters will continue to keep you informed ~ ~~ oT ,~~ ~.. _ ~ CityofBoulder