Hearn Avenue Interchange – Phase 3

Hearn Widening Aerial  Measure M

Update: April 2023

The Hearn Avenue Interchange - Phase 3 project design is fully completed. The California Department of Transportation (Caltrans) will be leading the construction for this project, which is anticipated to begin in early 2024.


The California Department of Transportation (Caltrans), in cooperation with the City of Santa Rosa and the Sonoma County Transportation Authority (SCTA), proposes to modify and reconstruct the US 101/Hearn Avenue interchange. The project would replace the existing Hearn Avenue overcrossing bridge with a new bridge to accommodate four traffic lanes with bicycle lanes and sidewalks on both sides of the roadway. The project would also increase the bridge height clearance and improve ramp connections to US 101. Continuous sidewalks and on-street bike lanes were included in the preliminary design; staff is considering the inclusion of a multi-use pathway or a separated class IV bike lanes to provide all user access between Dutton Avenue and Santa Rosa Avenue. 

Project design

The Hearn Avenue interchange is a critical investment in an area that is underserved and vital to Santa Rosa’s economy. The interchange serves 1) eight out of Santa Rosa’s top ten income and revenue generators, 2) two regionally designated Priority Development Areas where the City is targeting job and housing growth, and 3) the only SB 535 Disadvantaged Community in Sonoma County.

Drivers will benefit from the construction of a new bridge that meets minimum vertical clearance required by Caltrans design standards and improves traffic circulation for local roads and U.S. 101. These improvements will enhance the emergency preparedness of this critical evacuation route.

The current bridge condition—which lacks continuous bicycle and pedestrian facilities--creates a significant barrier to walking and bicycling.  This project aims to make walking and bicycling safe and convenient options for people of all ages and abilities, thus promoting public health and reducing greenhouse gas emissions from transportation. It will also dramatically improve traffic operations, thereby reducing greenhouse gas emissions created by vehicles idling and reduce vehicle miles traveled (VMT).

Project Schedule

Environmental document approved and design option selected 2016 - completed
Design Completed May 2022
Right-of Way (ROW) Completed May 2022
Start Construction - Caltrans Spring 2024*
End Construction - Caltrans Spring 2026*
  *Pending funding

Recent events

June 2017 - Design - awarded consultant contract

Project Document