Highway 166 reopens in SLO County. Here’s where to expect delays
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- Caltrans reopened Highway 166 after fire damage closed the road for 13 days.
- Construction crews replaced guardrails and repaired pavement, slopes and signs.
- Drivers should expect hour-long delays due to one-way traffic control and repairs.
Highway 166 reopened Wednesday afternoon after damage from the Gifford Fire caused the freeway to close for nearly two weeks.
According to a news release from Caltrans, Highway 166 had been closed between Highway 101 in Santa Maria and Perkins Road in New Cuyama since Aug. 1, when the major wildfire began burning.
Highway 166 runs along the Cuyama River, with San Luis Obispo County to the north and Santa Barbara County to the south.
On Wednesday, the California Department of Transportation cautioned drivers traveling on parts of Highway 166 to expect extensive delays.
Here’s what to know:
Why did Caltrans shut down Highway 166?
Caltrans closed the highway on Aug. 1 when a handful of spot fires ignited along the road.
Those blazes quickly expanded to a full-blown wildfire on both sides of the highway in SLO and Santa Barbara counties.
Since then, the Gifford Fire has grown into California’s largest fire of the year.
As of Wednesday afternoon, the Gifford Fire was 37% contained and had scorched 129,310 acres and destroyed four structures, according to Cal Fire.
Three civilians and seven firefighters had been injured in the blaze, Cal Fire said.
The cause of the fire was still under investigation as of Wednesday.
The highway was closed from Friday, Aug. 1, to Wednesday, Aug. 13, after Caltrans said a portion of the roadway, including some guard rails, had been damaged by the fire, making it unsafe to travel on.
Highway 166 reopens in SLO County
Caltrans reopened Highway 166 on Wednesday after completing essential repairs to fire-damaged stretches of the roadway.
Crews and contracted workers “inspected and repaired culverts, graded and improved pavement and shoulder areas, replaced signs, enhanced striping,” in advance of the opening, the state road agency said in the news release.
Caltrans also replaced 700-feet of damaged guard rails and end treatments within the Gifford Fire’s 20-mile burn scar.
The agency said construction will continue along parts of Highway 166 affected by the wildfire for the next several weeks.
Lane closures, traffic controls due to construction
Drivers should expect longer-than-usual delays while construction continues on Highway 166, Caltrans said.
One-way reversing traffic control will be underway at a 2.2-mile stretch of Highway 166 about 16 miles east of the junction of Highway 166 and Highway 101 in Santa Maria.
A pilot car will lead vehicles from six miles east of Tepusquet Road to Rock Front Ranch, the state road agency said.
At this section of Highway 166, the westbound lane will be shut down for 24 hours to complete “post-fire recovery efforts and ongoing construction activities, which includes rock scaling work intended to stabilize slopes left bare by the fire,” Caltrans said.
Caltrans said there is no timeline on when rockfall mitigation work could be complete.
Repair work on other parts of Highway 166 affected by the fire could also result in flagging operations with one-way reversing traffic control, the news release said.
How long could drivers be delayed on Highway 166?
Travelers driving on Highway 166 between Highway 101 and Highway 33 should expect delays up to an hour, according to Caltrans.
This story was originally published August 13, 2025 at 2:39 PM.
