Longhorn Dam Multimodal Improvements
In 2018, the City of Austin Public Works Department in partnership with Austin Transportation Department (ATD) began work on a Preliminary Engineering Report (PER) to evaluate the possibility of a new pedestrian and bicycle bridge over Lady Bird Lake, as well as a review of possible interim improvements to the existing bridge.
What's happening now?
Overnight closure: Saturday, August 7
All vehicular travel lanes on South Pleasant Valley Road on the Longhorn Dam bridge will be closed from approximately 10 p.m. on Saturday, August 7 to 6 a.m. on Sunday, August 8. The existing temporary trail detour will continue after the bridge re-opens and will remain in place while the west side of the bridge is closed for construction. Learn more.
Phase 2 Detour: Tuesday, June 29
The construction work zone will shift from the east side of the Longhorn Dam bridge to the west side on Sunday, June 27. Pedestrian and bicycle access across the west side of the bridge will remain intact during the work zone changes. Austin Transportation will establish a new temporary trail detour on Tuesday, June 29. The new detour will route people walking and biking across the lake to the newly built shared use pathway on the east side of the bridge using two newly constructed Pedestrian Hybrid Beacon signals. The detour will remain in place while the west side of the bridge is closed for construction.
Construction will continue to build out another shared use pathway on the west side of the bridge. View a video of construction progress.
Phase 1 Detour: Sunday, April 18
As work gets underway to build shared use pathways along South Pleasant Valley Road over the Longhorn Dam bridge, a "Phase 1" trail detour will begin on Sunday, April 18. The detour will reroute people on the east side of South Pleasant Valley Road between Krieg Field and Canterbury Street to accessible crossings at Cesar Chavez Street or Lakeshore Boulevard while the east side of the bridge is closed for construction.
Click to enlarge the detour map.
April 9, 2021
Construction is underway on interim improvements on the Longhorn Dam bridge. The changes on South Pleasant Valley Road (Cesar Chavez Street to Elmont Drive) are designed to provide significant near-term safety benefits while substantial design work begins on the new “wishbone” bicycle and pedestrian bridge over Lady Bird Lake. The interim improvements will address crash patterns resulting in more than $46 million in comprehensive crash costs over the last five years. The changes will provide better separation between people driving and people walking and riding bikes on South Pleasant Valley Road. Improvements include:
- New physical separation between north and southbound travel lanes throughout most of the project area to address head-on crash patterns.
- Reconfigured street space over the bridge to a single northbound traffic lane and two southbound lanes between the south Krieg Field entrance and Canterbury Street, with multiple new dedicated left turn lanes.
- A new 12-foot-wide shared use path on the west side of South Pleasant Valley Road and an 8-foot-wide shared use path on the east side.
September 2020 Update
Additional analysis along this section of South Pleasant Valley Road led staff to update the scope of the near-term interim improvements to align with the safety needs of people driving, rolling, and walking in the area. Review the virtual open house to learn about these updates.
Actualización de septiembre de 2020
El análisis de esta sección de South Pleasant Valley Road llevó al personal a actualizar el alcance de las mejoras provisionales para alinearlas con las necesidades de seguridad de las personas que conducen, ruedan y caminan en el área.
Preliminary Engineering Recommendations
Final Preliminary Engineering Report, July 2020
This plan evaluates the feasibility of new multi-use pedestrian bridge alternatives spanning the Colorado River near the Longhorn Dam and associated trail connectivity improvements. Click on the links below to read the recommendations:
- View the Longhorn Dam Multimodal Improvements Preliminary Engineering Report
- Appendices A: Concept Drawings
- Appendices B: Cost Estimate
- Appendices C: Preliminary Geotechnical Bridge Foundation Recommendations Memo
- Appendices D: Public Meeting Input Summary
- Appendices E: Preliminary Constraints and Permitting Analysis Report
- Appendices F: Hydraulic Memo
- Appendices G: Utility Layout
- Appendices H: Best Practice for Dam Owners
December 2019 Open House & Project Survey
Austin Public Works, Austin Transportation, and Austin Parks and Recreation departments hosted a third open house on December 10, 2019. Information was presented about the recommended bridge alternative, the project's future design and construction phases, and interim improvements.
September 2019 Project Update
In summer 2019, Austin Transportation and Public Works Department shared five bridge alternatives that were developed from community input received in late 2018. A project survey was available from June 10 through July 10 to collect community feedback on the different alternatives, including a no build option, as well as the proposed interim improvements.
Of the five bridge alternatives and the no build option, Alternative B (Wishbone shaped bridge that connects to the shore at three points) received the most overall support, with 742 responses selecting this alternative as their top choice and 1,419 responses indicating they were “very comfortable” or “somewhat comfortable” with Alternative B.
City staff, recognizing that Alternative B (Wishbone) received the highest levels of public support, will conduct further technical analysis and evaluation of public feedback before bringing a recommended alternative to the public at a third and final community open house this fall. A refined package of interim improvements will also be presented at the community open house. Funding for the interim improvements is available from the 2016 Mobility Bond.
Public Meeting 1 - Nov 13, 2018
In fall 2018, the project team held an initial public meeting and released an online survey to collect feedback on needs and potential interim improvements. Over 550 responses were received and analyzed.
Public Meeting 2 - June 10, 2019
Input received from the community in November and December 2018 was evaluated to develop alternatives for public review. At the second public meeting, the project team presented and collected public feedback on five alternatives as well as potential interim improvements to the existing bridge.
A survey was available from June 10 to July 10 for feedback on the five alternatives and potential interim improvements. Survey results are being evaluated by staff.