The final phase of the Highway 101 widening project is set to begin in the spring, with the final segment near the Old Coast Highway.
The final phase of the Highway 101 widening project is set to begin in the spring, with the final segment near the Old Coast Highway. Credit: Daniel Green / Noozhawk photo

After years of work, the Highway 101 widening project will enter the last stage of construction in 2026 and potentially be completed by late 2028. 

The final stage of the massive project to add a third lane between Santa Barbara and Carpinteria is set to start next spring. That phase, called Santa Barbara North, comes after crews finish the current construction section in Montecito.

There is no start date announced for that last stage yet, according to project spokeswoman Kirsten Ayars.

The next stage of the project will include the addition of a third lane between Hermosillo Road and Salinas Street, which is a high-occupancy vehicle lane during peak hours. Crews also will build a new interchange at Cabrillo Boulevard with two new bridges and a new southbound on-ramp near Los Patos Way. 

The southbound off-ramp at Los Patos Way will be closed permanently.

A new teardrop roundabout will be built on Cabrillo Boulevard and next to the Highway 101 northbound ramps near the Montecito Country Club along Old Coast Highway. 

Ayars said crews first will focus on the shoulders of the freeway. They then will move to the inner lanes and work their way out.

“We have to go in at the beginning of the project and build up the shoulders,” Ayars said. “That enables us to shift the traffic lanes around so that we can build this brand-new project while we keep the freeway open with two lanes in each direction during the day.”

Ayars said the goal is to time the beginning of the next phase to allow highway on-ramps and off-ramps in Montecito to open to vehicles while crews close ramps in the next area near Cabrillo Boulevard.

A timeline and rendering show the final stage of the Highway 101 widening project. Credit: Courtesy graphic

To prepare for the next stage of the project, workers will be clearing vegetation and trees along the freeway. They will work at night, and will close that portion of the freeway and ramps to conduct the work.

“That tree clearing work will mostly (be done) at night in January, and it involves chainsaws,” Ayars said. “It will be noisy. So, we want the public to be aware that will be going on around the Cabrillo interchange.”

Highway 101 Project Progress

The Highway 101 project has been split into multiple parts. The section known as Santa Barbara South is a portion of the highway that goes through part of Santa Barbara and Montecito. The section is nearing completion, and workers will finish the median by the middle of 2026, according to Ayars. 

Crews have reduced the number of lanes between Olive Mill and Hermosillo roads as they continue work in that area. They also will be closing on-ramps and off-ramps through the week for roadwork. 

The entire estimated cost for the upgraded freeway is $700 million. The project was originally split into multiple segments to allow local governments to pay for each section individually as construction began on each part.

Phase One of the project began in 2008 near Milpas Street and Hot Springs Road. The second phase then moved to the section of Highway 101 between Mussel Shoals and Carpinteria. The third phase included construction between Linden Avenue and Casitas Pass.

Phase Four of the project began in Carpinteria and made its way up to Santa Barbara, completing construction in Padaro and Summerland before beginning work in Montecito and Santa Barbara. 

The project was also split into Santa Barbara South and Santa Barbara North.

For the full list of road closures and other updates on the project, visit sbroads.com. 

  • Northbound Highway 101
    • Monday and Tuesday, Dec. 8-9, 8 p.m. to 5 a.m., one lane: Sheffield Drive to Cabrillo Boulevard, on- and off-ramps at Sheffield Drive, San Ysidro Road, Olive Mill Road, Hermosillo Drive and Cabrillo Boulevard. Crews will refresh lane and ramp striping. There will be alternating lane closures of the on- and off-ramps.
    • Wednesday & Thursday, Dec. 10-11, 8 p.m. to 5 a.m., one lane: Sheffield Drive to Cabrillo Boulevard
    • Daytime closures:
      • Monday through Thursday, Dec. 8-11, 9 a.m. to 6 p.m., one lane: South Padaro/Santa Claus Lane to North Padaro Lane
  • Southbound Highway 101
    • Monday and Tuesday, Dec. 8-9, 8 p.m. to 7 a.m., one lane: Cabrillo Boulevard to Sheffield Drive, on- and off-ramps at San Ysidro Road and Sheffield Drive. Crews will refresh lane and ramp striping. There will be alternating lane closures of the on- and off-ramps.
    • Wednesday and Thursday, Dec. 10-11, 8 p.m. to 7 a.m., one lane: Cabrillo Boulevard to Sheffield Drive
    • Daytime closures:
      • Monday and Tuesday, Dec. 15-16, 9 a.m. to 3 p.m., off-ramp at Sheffield Drive
      • Wednesday and Thursday, Dec. 17-18, 8 p.m. to 7 a.m., one lane: Cabrillo Boulevard to Sheffield Drive, off-ramp at San Ysidro Road (consecutive closure with the off-ramp at Spring/Olive Mill Road; see map below)
    • On-ramp at Posilipo Lane, closed until spring 2026; drivers can use the southbound on-ramp at Sheffield Drive
    • On-ramp at Olive Mill Road, closed until spring 2026, (consecutive ramp closure with the on-ramp at Posilipo Lane); drivers can use the detour on North Jameson and the on-ramp at Sheffield Drive
    • Off-ramp at Spring/Olive Mill Road, closed until spring 2026; drivers can use the off-ramp at San Ysidro Road
  • South Jameson Lane between Eucalyptus Lane/San Ysidro Road and Posilipo Lane
    • Wednesday, Dec. 10, 7 a.m. to 3 p.m.; flaggers will direct traffic on South Jameson Lane for bridge work 
  • North Jameson Lane between Sheffield Drive and Olive Mill Road
    • Periodic daytime flagging for fence repairs

— Noozhawk staff writer Daniel Green can be reached at dgreen@noozhawk.com.