Hwy. 101 lanes to close in SLO County. Take these detours to avoid roadwork
AI-generated summary reviewed by our newsroom.
- Caltrans begins overnight lane closures on Hwy. 101 for safety upgrades near Paso Robles.
- Crews construct underpass and frontage roads to eliminate risky cross-traffic turns.
- Project targets fatality-prone Wellsona Road intersection; completion set for 2026.
Part of Highway 101 will close overnight as crews continue construction on one of San Luis Obispo County’s most dangerous intersections.
Crews are working on a $12.2 million project that was delayed for several years before work got underway in January.
Caltrans plans to construct a new 112-foot underpass beneath Highway 101, as well as a frontage road connecting the underpass with Wellsona Road on both sides of the highway, the state roads agency said in a news release.
The underpass will remove the need for drivers to make left turns or drive straight across traffic on Highway 101 near the San Paso Truck Stop between Paso Robles and San Miguel, according to the California Department of Transportation.
Here’s what to know:
Where are Highway 101 lane closures?
Caltrans will close alternating lanes of Highway 101 in both directions near the Wellsona Road intersection about five miles north of Paso Robles, the agency said.
While the roadwork is underway, one lane will stay open to drivers in both directions overnight, Caltrans said.
When will freeway lanes shut down?
The Highway 101 lanes will be blocked to traffic from 7 p.m. on Monday, Sept. 8, to 6 a.m. on Tuesday, Sept. 9, according to Caltrans.
A detour will be available for bicyclists, the state road agency said, and the San Paso Truck Stop will remain open and accessible for travelers.
New phase begins on construction near Paso Robles
Caltrans is closing the Highway 101 lanes to adjust temporary barriers and pavement delineation in order to begin construction of the northbound bridge.
Crews plans to build the new bridge from Monday, Sept. 8, through mid-January 2026.
The northbound bridge is part of the third phase of construction on the Wellsona Road Safety Improvement Project, Caltrans said.
The roadwork is intended “to reduce the number and severity of collisions” at the crossroads of Highway 101 and Wellsona Road just north of Paso Robles, according to the news release.
The intersection of Highway 101 and Wellsona Road is the second-deadliest crossroad in San Luis Obispo County in terms of the number of traffic fatalities over the past decade, The Tribune previously reported.
Eight people died in vehicle crashes at the intersection between 2014 and 2024, which puts the fatal collision rate at the crossing higher than the state average, Caltrans said.
CalPortland Construction of Santa Maria is the contractor for the Wellsona Road Safety Improvement Project, according to the state road agency.
Where are detours to avoid roadwork, access Wellsona Road?
Access to Wellsona Road from Highway 101 has been modified since construction began, the news release said.
Detours will remain the same during Caltrans’ third phase of construction.
Southbound Highway 101 travelers will have direct access to west Wellsona Road, according to Caltrans, while northbound motorists can travel onto west Wellsona Road by using a left turn pocket.
Caltrans has a detour in place for southbound Highway 101 travelers heading onto east Wellsona Road. Northbound drivers can use the right turn lane to access east Wellsona Road, according to Caltrans.
When will construction be complete?
Caltrans estimates the Wellsona Road Safety Improvement Project will be finished in early 2026.
