US 101/Hearn Avenue Regional Multimodal Interchange

For the latest news see Project Updates below -

Project Scope

This is a rendering of the project on an aerial image. It shows the project limits from roughly Corby Avenue crossing US 101 to Santa Rosa Avenue, the southbound US 101 off-ramp to where it intersects with Corby Avenue, and the section of Corby Avenue from that intersection to Hearn Avenue. The rendering shows the increased width that will include additional travel lanes, raised median, sidewalks and bikeways, and provides a cross section view of the roadway with these improvements. The rendering also shows how the project will connect to the SMART multi-use path to the west and proposed ADA elements at the intersections within the project limits.The US 101 Hearn Avenue Regional Multi-modal Interchange Project will demolish and reconstruct the Hearn Avenue interchange overcrossing in the same location to increase vertical clearance over US Hwy101, widen the overcrossing to provide two vehicle lanes in each direction, a median, sidewalks, and two Class IV bike lanes extending to Corby and Santa Rosa Avenue. The project will also widen the southbound US 101 off-ramp with turning lanes at its intersection with Corby Avenue, add lanes at the intersections of Hearn Avenue/Corby Avenue and Hearn Avenue/Santa Rosa Avenue, and add pedestrian curb ramps and crosswalks that comply with the American Disability Act and incorporate protected intersection facilities for bike crossings and detection to reduce potential conflicts between bikes and vehicles.

The project is the final phase of the Hearn Avenue and Santa Rosa Avenue Complete Streets Project to provide roadway widening, pedestrian, and bicycle improvements intended to improve mobility in southern Santa Rosa.

Project Purpose

The project will relieve traffic congestion and improve regional traffic operations, including providing multimodal access and connectivity adjacent to the Highway 101 and Hearn Avenue intersection.

Current Conditions:

  • Existing Hearn Avenue overcrossing is one lane in each direction with no shoulders
  • Insufficient capacity for vehicles leads to queuing back onto the mainline southbound US 101 auxiliary lane during peak periods
  • Congestion and lack of shoulders delays emergency response times
  • No sidewalk on the north side and discontinuous sidewalk on the south side
  • No bike facilities on Hearn Ave overcrossing
  • Nonstandard vertical clearance over US 101
  • Non-crashworthy bridge railings

Project Benefits:

  • Improve local traffic circulation and regional traffic operations (resulting in improved first responder access and response time)
  • Improve multimodal access, connectivity, and operations
  • Improves access to essential goods, services and jobs
  • Improves access to recreation
  • Improves access to schools and adult educational and career development
  • Improves access to public transit and transit travel times
  • Improve overall safety of the facility

Project Updates

Hearn Avenue Overcrossing at U.S. Highway 101 in Santa Rosa Various Overnight Onramp/Offramp and Lane Closures

Starts Sunday, July 14 through Saturday, July 20, 2024

Caltrans has scheduled various overnight onramp/offramp and lane closures on U.S. 101 and at the U.S. 101 Hearn Avenue Overcrossing in Santa Rosa. One traffic lane on U.S. 101 in each direction will remain open at all times.

As part of the construction work to widen the existing Hearn Avenue overcrossing, this coming week, crews will work on drainage systems, which will require various closures on and near the overcrossing.

Southbound U.S. 101 Offramp at Hearn Avenue CLOSED overnight Starts Sunday, July 14

The southbound U.S. 101 off-ramp at Hearn Avenue will be closed between 9:00 PM and 5:00 AM on July 14, 15, and 16. Detour signs will be posted with motorists directed to take the following detour;

  • Exit at Todd Road
  • Turn left onto southbound South Moorland Avenue
  • Turn left onto eastbound Todd Road overcrossing
  • Turn left onto westbound Todd Road
  • Turn right onto the northbound 101 on-ramp
  • Take the northbound 101 off-ramp to eastbound Yolanda Avenue
  • Turn left onto northbound Santa Rosa Avenue
  • Return to Hearn Avenue

Also, one traffic lane on southbound U.S. Highway 101 will be closed from Yolanda Avenue to Hearn Avenue between 10:00 PM and 6:00 AM on July 14, 15, and 16.

Northbound U.S. 101 Onramp at Hearn Avenue CLOSED overnight Starts Wednesday, July 17

The northbound U.S Highway 101 on-ramp at Hearn Avenue will also be closed between 9:00 PM and 5:00 AM on July 17, 18, and 19. Detour signs will be posted with motorists directed to take the following detour;

  • Take the northbound U.S. Highway 101 on-ramp at Baker Avenue

One traffic lane will also be closed on northbound U.S. Highway 101 from Yolanda Avenue to Hearn Avenue between 10:00 PM and 6:00 AM on July 17, 18, and 19.

Santa Rosa Avenue bike and pedestrian detour route.

Santa Rosa Avenue bike detour plan map


Turn Pockets to Close at Hearn/Corby Ave. Intersection in San Rosa for Nine Months, Making Room to Widen Overcrossing

Closures begin in early hours on Wednesday, May 29, 2024

As part of the Hwy 101/Hearn Avenue Overcrossing Replacement Project in Santa Rosa, Caltrans will close the right-turn lane from westbound Hearn Avenue to northbound Corby Avenue, and the left turn pocket from southbound Corby to eastbound Hearn, before the start of the morning commute on Wednesday, May 29, 2022.

The turn pockets will be closed for nine months, providing space for Caltrans to build the northern section of the new Hearn Avenue Overcrossing.Hearn Avenue Interchange with Corby

During the closure, the single westbound lane on Hearn Avenue will serve vehicles turning right or left onto Corby and vehicles traveling straight on Hearn Avenue.  Westbound motorists should allot more travel time during the closure, as capacity on Hearn Avenue will be reduced.

Also, Caltrans will close the left turn pocket on southbound Corby, making the single southbound lane serving traffic turning left or right onto Hearn or through traffic on Corby.

The Hearn Avenue Project is a partnership between Caltrans Sonoma County Transportation Authority (SCTA) and the City of Santa Rosa to upgrade the existing overcrossing that spans U.S. Highway 101 with a single eastbound and westbound lane and includes only a small sidewalk for pedestrians.

The new $43.7 million project will include two eastbound and westbound lanes and feature two sidewalks, two Class 4 bicycle lanes, and other elements designed to reduce congestion and better serve people who walk and bike in southern Santa Rosa. 

This project is an example of Caltrans’ Complete Streets Program, which adds multimodal upgrades to new projects when feasible.

The project was first envisioned in the 1990s and became feasible in 2004 when Sonoma County passed Measure M, a quarter-cent sales tax to fund transportation upgrades. In 2020, voters approved an extension of Measure M. 

The SCTA contributed $17.2 million through Measure M funds, and the City of Santa Rosa contributed $9.4 million. 

The project also received $17 million in state funds, $8.6 million through the Senate Bill (SB) 1 LPP competitive program, $5 million through SB 1 Local Partnership Program (LPP), and $3.4 million from the State Transportation Improvement Program (STIP).

When completed in late 2025, the Hearn Avenue Overcrossing will comply with new regulations to allow taller vehicles to pass beneath. 

Groundbreaking

Click image below for video of project groundbreaking.
A group of representatives from Caltrans, Sonoma County Transportation Authority, and local elected officials stand behind a pile of gravel and toss shovelfuls of dirt as part of the US 101 Hearn Ave Overcrossing Project's groundbreaking ceremony.

Project Contact

For more information, contact Caltrans Sonoma County Public Information Officer Jeffrey Weiss.

Jeffrey.weiss@dot.ca.gov