There are two related projects in the area. Projects will help mitigate potential future flooding and improve multimodal travel connections
The 19th Street and Fourmile Canyon Creek Underpass project, part of a larger Fourmile Canyon Creek Flood Mitigation project, will build a bicycle and pedestrian underpass and help provide additional flood capacity in the future.
The 19th Street Multimodal Improvements project will help improve travel connections between Norwood and Sumac avenues.
2017-2019
2020-2022
2023-2024
Learn more about each project below:
Beginning, Monday, July 22, Quince Avenue at 19th Street will be closed to travel for two weeks until Monday, Aug. 5. This closure will allow for the reconstruction of the 19th Street and Quince Avenue intersection for the 19th Street Multimodal Improvements project. During this time, northbound 19th Street vehicles and RTD bus service will detour via Sumac Avenue west to Broadway.
We anticipate completing this work before the Boulder Valley School District fall semester starts to limit impacts to Crest View and the surrounding school communities. The standard detour route via Quince Avenue will resume after Aug. 5.
View a large version of the map.
This is a text alternative to the image. During construction, 19th Street will be closed to northbound vehicles, bikes, and RTD bus service at Sumac Avenue with a detour at Quince Avenue (the detour route will be via Sumac Avenue from July 22 through August 5 for the reconstruction of the 19th Street and Quince Avenue intersection). The southbound 19th Street travel lane and RTD 204 bus stops will remain open. Northbound RTD 204 bus stops at Riverside Avenue and Upland Avenue will temporarily close. The nearest open northbound transit stops will be at Poplar Avenue and Avocado Road. Expect sidewalk closures, pedestrian detours, and delays when traveling in the area. The southbound sidewalk in front of Crest View Elementary is closed indefinitely. Northbound and southbound pedestrians and bikes should use alternative route in the area or the detour route through Crestview Park.
We are committed to sharing construction updates on this webpage. Construction impacts may change due to changing and unforeseen conditions. Major construction began in March 2024, and will last approximately two years. View the detour map.
Travelers can expect long-term traffic impacts due to lane closures on 19th Street between Sumac and Upland avenues, anticipated to last for two years beginning on March 25, 2024:
Per City of Boulder Revised Code 9-5-3, noise levels of 55 decibels are allowed between 5-11 p.m., and 50 decibels are allowed between 11 p.m. to 7 a.m. The results of the first sound testing of the generators completed on the evening of Tuesday, April 16, were the following:
Travelers can also expect impacts between Norwood Avenue and Sumac Avenue:
For updates, view the city's Cone Zones map.
Along with flood mitigation, the 19th Street and Fourmile Canyon Creek Underpass project will improve travel on 19th Street, an important multimodal connection in north Boulder. The city will construct a new bicycle and pedestrian underpass connecting Tamarack and Upland avenues; replace and widen the 19th Street bridge over Fourmile Canyon Creek; improve transit stops; upgrade the on-street bikeable shoulder to a buffered bike lane; construct a new sidewalk; and install curb and gutter. Construction began in 2024.
19th Street from Norwood to Sumac avenues is an important multimodal travel corridor in north Boulder. This project will help improve connections for all travel modes by constructing a new sidewalk and completing missing sidewalk links, upgrading the on-street bike facility to a buffered bike lane, enhancing transit stops, installing curb and gutter, and installing speed cushions, which are similar to speed bumps.
Construction on this project began in April 2024, with light construction activities with the contractor potholing existing utilities.
From Norwood Avenue to Sumac Avenue on both the east and west sides of 19th Street, the 19th Street Multimodal Project will:
From Sumac Avenue to Yarmouth Avenue:
As part of a separate effort, in coordination with city staff, Xcel completed undergrounding of Xcel overhead utilities from Norwood to Upland avenues.
19th Street from Norwood to Sumac avenues is an important multimodal travel corridor in north Boulder. Currently, there is an on-street bikeable shoulder and an existing sidewalk on the east side. These were constructed in the 1990s, but the sidewalk does not meet current city design standards. The on-street bikeable shoulder ends at Violet Avenue and is then a designated bike route from Violet Avenue north to Yarmouth Avenue. On the west side of 19th Street, the sidewalk is not continuous from Yarmouth to Norwood avenues.
19th Street from Norwood to Yarmouth avenues has been given a high priority on the city's Missing Sidewalk Links program. The Missing Sidewalk Links program identifies, prioritizes and constructs missing sidewalk segments to provide a continuous pedestrian network and ensure a safe walking environment.
In 2014, the city submitted an application for federal funding to construct a 5-foot-wide sidewalk, install curb and gutter on the east side and complete the missing sidewalk links on the west side of this corridor. The project received funding from the Colorado Department of Transportation (CDOT) Transportation Alternatives Program (TAP) and the Federal Highway Administration's Safe Routes to School grant program for the estimated project costs.
The city is also planning improvements along Fourmile Canyon Creek to improve safety and accessibility to Crest View Elementary School by completing an underpass at 19th Street and Fourmile Canyon Creek. Learn more on the Fourmile Canyon Creek webpage. The two project teams are coordinating efforts.
Further exploration of the Wonderland Creek floodplain was conducted from late fall 2018 through summer 2019 to understand expectations for achieving the floodplain development permit requirements. Two additional alternatives were included in the project's Community and Environmental Assessment Process (CEAP) to meet the identified facility type for 19th Street through the Low-Stress Walk and Bike Network Plan and to address Transportation Advisory Board feedback provided in August 2018. All design alternatives also now incorporate the features needed to meet floodplain mitigation requirements.
On Nov. 21, 2019, the project team hosted an open house, with 78 people in attendance, to share the five conceptual design alternatives being considered for the project and asked for the community’s feedback on a preferred alternative and reasons for that preference. There was a comment form available at the open house and online The goal was to learn which option was preferred so we can balance the needs of the community and meet the goals of the Transportation Master Plan. Your input was utilized as a final concept is selected.
Thanks to all who provided their input on the 19th Street Multimodal Improvement Project! We received a total of 58 completed comment forms. Whether you completed it at the open house on November 21, or provided it online, we appreciate your feedback.
Both the meeting comment forms and the online comment forms expressed a preference for Alternative 4 which includes a combination of attached and detached sidewalks and buffered bike lanes.
View full image. This is a text alternative to the image: typical cross-section of the corridor, facing north. From left to right: 6-foot sidewalk varying from 0-2-foot colored concrete, 2-foot curb and gutter, 5-foot bike lane, 2-foot painted buffer, 10-foot travel lane in one direction, 10-foot travel lane in opposite direction, 2-foot painted buffer, 5-foot bike lane, 2-foot curb and gutter, 0-4-foot landscape strip transition, 6-foot sidewalk next to existing utilities.
During the city's annual capital improvements budgeting process, an interdepartmental team identified the 19th Street project to utilize the city’s Community and Environmental Assessment Process (CEAP). The CEAP is a formal review process to consider the impacts of public development projects. The purpose of the CEAP is to assess potential impacts of conceptual project alternatives in order to inform the selection and refinement of a recommended conceptual design alternative. The CEAP provides the opportunity to balance multiple community goals in the design of a capital project by assessing a project against the policies outlined in the Boulder Valley Comprehensive Plan, the Transportation Master Plan, departmental master plans, and sub-community or area plans (if applicable). The CEAP also ensures that environmental, social and fiscal impacts of projects are minimized and assures compliance with city policies, plans and regulations.
The final CEAP for the 19th Street project was reviewed and provided official recommendation by the City of Boulder CEAP Review Group, the city's Transportation Advisory Board and City Council.
Construction work hours for the 19th Street and Fourmile Canyon Creek Underpass project are typically between 8 a.m. and 5 p.m., Monday through Friday. However, this schedule is weather and task-dependent. Work may extend past 5 p.m. on a case-by-case basis with the city project manager's approval to ensure work tasks are completed in a safe and reasonable manner. Weekend work is also possible and will also be approved on a case- by-case basis by the city project manager. Notice of weekend work will be shared in advance by the Thursday prior via the project webpage.
Construction activities involve heavy equipment and machinery, and includes equipment and machinery needed for construction itself and for receiving deliveries to the job site. Community members should expect the use of heavy machinery during the typical work hours of 8 a.m. and 5 p.m., and when evening and weekend work has been approved by the city’s project manager. Additionally, neighbors should anticipate construction crews on the job site before 8 a.m. to hold safety meetings and prepare for the day's work. Independent, third-party trucking companies may arrive to the job site prior to 8 a.m. for deliveries, but will be instructed to wait until 8 a.m. to make their deliveries.
The Topaz Drive and Garnet Lane intersection has been closed to through traffic since the late 2000s in coordination between the City of Boulder and Boulder County (north of the intersection on Garnet is city jurisdiction, while south of the intersection on Garnet and Topaz is County jurisdiction). The city and County have decided to not open the intersection full-time to vehicles during construction due to costs associated with opening the intersection and limited benefits to traffic operations that would result.
However, the city has been approved to allow vehicles through the intersection with flaggers during the most impactful construction activities at the 19th Street and Riverside intersection during the 19th Street Multimodal Improvements project. More information about when this will occur will be shared on the project webpage.
The new underpass will allow students, families, and neighbors walking and biking to cross 19th Street completely separate from vehicle traffic, to access Crest View Elementary, Crestview Park, and other destinations to the east and west. New LED lighting will also be installed in the underpass and will stay on 24/7 to prevent illicit activities.
If, at any time, a community member believes there is an immediate threat to his/her/their safety or the safety of another person, we ask they call 9-1-1. A police officer will respond and take appropriate action. If a community member sees something that is concerning but not necessarily threatening, we encourage use of the 303-441-3333 police line, which is the city’s non-emergency phone number.
