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 1, 2, and 3 are complete. Phase 4 is in construction.

Phase 1 - Milpas to Hot Springs



  • Hwy 101 widening (2 miles)
  • Milpas St. Interchange
  • Montecito Roundabout
  • Cacique St. connected
  • Sycamore Creek Bridges
  • Pedestrian & bike access
  • Cabrillo Bridge Widening

$96 million

2008 - 2012

Measure D, state & federal gas taxes

Project Location

Between Santa Barbara and Mussel Shoals, Highway 101 is being expanded to include new carpool lanes and operational improvements. The phases are color coded above.

Click for Phase 1 Highway 101 - Milpas to Hot Springs

Completed 2012

Click for Phase 2 Highway 101 - Milpas to Hot Springs

Completed 2015

Click for Phase 3 Highway 101 - Linden to Casitas Pass

Completed 2020

Click for Phase 4 Highway 101 - Carpinteria to Santa Barbara

In Construction