Santa Barbara to Mussel Shoals Home

Widening Projects

SBCAG and Caltrans have undertaken widening 16 miles of Highway 101, known as Highway 101: Santa Barbara to Mussel Shoals, to add carpool lanes and address a narrow portion of Highway 101 that currently has two lanes in each direction. The project is phased as depicted on the Project Location Map below. Phases I and 2 are complete. Construction on Phase 3 is nearly complete, and Phase 4 construction is underway.

Carpinteria to Santa Barbara

Design, Environmental Review


  • Hwy 101 widening (10.9 miles)
  • Carpool lanes added
  • Cabrillo Blvd Interchange
  • Sheffield Dr Interchange
  • Rehabilitate existing lanes
  • Sound Walls
  • Creek Bridges

Approximately $700 million
*forecasted construction costs


Measure A, state & federal gas taxes

Click on the maps below to view or print segments of Phase 4.

Phase 4A Completed Carpinteria

Highway 101: Carpinteria added a peak-period carpool lane to the freeway in each direction within the City of Carpinteria. The new lanes tie into recently added third lanes to the south and upcoming projects to the north. New bridges were built over Franklin and Santa Monica Creeks. There is new freeway on- and off-ramp improvements at Santa Monica Road, Carpinteria Avenue, and Reynolds Avenue. Six new sound walls are constructed to reduce freeway noise for neighbors. On local streets, improvements to the intersections at Santa Monica Road & Via Real, Reynolds & Carpinteria Avenues, and Bailard Avenue & the freeway ramps are complete.

Phase 4B Padaro

Highway 101: Padaro will widen Highway 101 to 3 lanes in each direction between the City of Carpinteria and Summerland. The project includes new bridges over Toro and Arroyo Parida Creeks. At the South Padaro Lane Undercrossing, the bridge and on- and off-ramps will be replaced. At the North Padaro Lane Interchange, new on- and off-ramp improvements will be built. There are also three new sound walls.

Phase 4C Summerland

Highway 101: Summerland added a peak-period carpool lane in each direction for 1.7 miles. The new lanes will open at the end of construction of the Highway 101: Padaro segment since Summerland is located between two construction areas. At the Evans Avenue Undercrossing, a new bridge segment connects the freeway bridges and is accompanied by pedestrian, bike lane, and lighting improvements underneath Highway 101. At the Sheffield Drive Interchange, new freeway bridges were built along with new right hand on- and off-ramps on southbound Highway 101 and improved northbound on- and off-ramps. The on-ramp at Wallace Avenue was replaced and a new retaining wall was added to accommodate the wider freeway. There are also two new sound walls. Landscaping is ongoing.

Montecito Phase 4D Montecito

Highway 101: Montecito will add a new peak-period carpool lane in each direction from the Romero Creek Bridge north to Olive Mill Road. There will be new on- and off-ramps and auxiliary lanes (lanes connecting on-ramps and off-ramps to improve merging) between San Ysidro and Olive Mill Roads. New bridges will be built over Romero, San Ysidro, and Oak Creeks.

Phase 4E Santa Barbara

Highway 101: Santa Barbara will add a new peak-period carpool lane in each direction from Olive Mill Road to Sycamore Creek. The Cabrillo Boulevard Interchange will be reconstructed with new bridges and right-hand freeway ramps, including a new northbound off-ramp and new southbound on-ramp. There are two new proposed sound walls. Construction will be phased into south and north segments to coincide with funding.