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.

  1. Community Engagement


  2. Design


  3. Build


Project Overview

19th Street and Fourmile Canyon Creek Underpass Project


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 Impacts

Construction impacts may change. For updates, view the city's Cone Zones map. Major construction is anticipated to begin 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:

— The northbound lane is anticipated to close to travel starting from Monday, March 25.

— Both the northbound and southbound lanes are anticipated to close to travel from 8 a.m. on Friday, March 29 through 5 p.m. on Saturday, March 30.

— While the southbound lane is anticipated to reopen to travel after 5 p.m. on March 30, the northbound lane will remain closed to travel for the duration of the project.

A detour map. Alt text provided in image caption.

View a large version of the map. View a Spanish version of the map
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 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 will remain open at most times. If both the east and west sidewalks on 19th Street are closed due to work, a pedestrian detour will be in place through Crestview Park.


Along with flood mitigation, this 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 Updates

View the city’s Cone Zones map for updates on construction and travel impacts.

19th Street Multimodal Improvements Project


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 is anticipated to begin in late spring or early summer 2024.

Project Improvements

From Norwood Avenue to Sumac Avenue on both the east and west sides of 19th Street, the 19th Street Multimodal Project will:

  • Install continuous sidewalks and curb & gutter on both sides of 19th Street from Norwood to Sumac avenues.
  • Convert the existing bikeable shoulders to a buffered bike lane facility.
    • Note: On-street parking will not be permitted with the transition from a bikeable shoulder to a bicycle lane with the addition of a curb and gutter.
  • Upgrade or install pedestrian curb ramps.
  • Plant new landscaping and trees to replace trees that will be removed in conjunction with this project.
  • Install a new storm sewer pipe and drainage inlets from Sumac Avenue to Wonderland Creek.
  • Replace the existing Wonderland Creek culvert with a 24-foot-wide by 5-foot-high culvert to meet floodplain development permit requirements.
  • Improve the bus stop.
  • Install traffic calming through "speed cushions" to reduce vehicle travel speeds while accommodating emergency response vehicles.
  • Reduce the posted speed limit from 30 mph to 25 mph.
  • Install enhanced pedestrian crossings where city guidelines identify them to be appropriate. All enhanced crossings installed through the project will include adequate street lighting and signage (State Law — Yield to Pedestrian).

From Sumac Avenue to Yarmouth Avenue:

  • Plan for future multimodal improvements, to be constructed once funding becomes available.

As part of a separate effort, in coordination with city staff, Xcel completed undergrounding of Xcel overhead utilities from Norwood to Upland avenues.

Summer 2022 Video Update

Project Background

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.

Selected Alternative: Concept 4

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.

The 19th Street Selected Alternative: Concept 4. Long description in image caption.

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.

Community and Environmental Assessment Process

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.

Previous Community Engagement Events

  • The city held an open house on Thursday, April 19, 2018, for the public to view project alternatives, provide feedback and inform the selection of the preferred design. An online questionnaire was also open until May 14, 2018.
  • The project team attended the Community Cycles Advocacy Committee meeting on Feb. 5, 2018, to better understand their comments submitted through the "A Vision for 19th Street" report.
  • The project team participated in a WTS-Centennial Middle School Transit Study field trip with Centennial students on Jan. 23, 2018, to better understand their perception and use of transit. The field trip traveled from Centennial along Norwood Avenue to the transit stops at Norwood Avenue and 19th Street.
  • The project team hosted two site walks on Wednesday, Sept. 27, and Thursday, Sept. 28, 2017, to learn more about the project area and gather ideas for multimodal improvements.
  • The project was featured at the May 22, 2017, North Boulder Public Works Open House.
  • The project was included at a North Boulder Open House Meeting and Boulder Valley Comprehensive Plan (BVCP) Listening Session on Nov. 18, 2015. The project background and map were presented at the open house.