Key 101 ramp to close over weekend

A closure of part of Santa Rosa’s most heavily used freeway interchange this weekend has the potential to cause traffic backups of up to 40 minutes, officials are warning.

The Highway 12 onramp to northbound Highway 101 will be closed 5 p.m. Friday to 6 a.m. Monday, and a similar closure is planned for the following weekend.

“It carries a lot of traffic and the message is if people can avoid Highway 12 and 101, then take something else,” said Suzanne Smith, executive director of the Sonoma County Transportation Authority. “I think it has the potential to cause people distress.”

The good news is that this will be the last major closure by Caltrans as the freeway widening project winds down, Smith said.

“By mid-November we are looking at using the whole new facility,” Smith said.

The northbound onramp is being closed for paving.

The eastbound Highway 12 onramp to southbound Highway 101 also will be closed 7 to 11 p.m. Friday.

These are in addition to the closure of the Third Street offramp from northbound Highway 101, which is expected to last until Oct. 8, and the closure of the southbound Highway 101 onramp at Third Street, slated to last until Oct. 31.

Caltrans is advising westbound Highway 12 traffic to take the South E Street exit and eastbound traffic to get off at Fulton Road or Dutton Avenue or take Highway 101 south and exit at Baker Avenue, and then take city streets to get on at other onramps.

The closures of highway access points, city streets and changes in lane patterns have been commonplace during the three years of construction on the $111.5 million project that adds a carpool lane in each direction from Highway 12 to Steele Lane.

It also has caused some traffic snarls before motorists adjust their driving patterns.

This weekend closure, however, could catch visitors off guard, so Caltrans is putting information in area restaurants and gas stations.

The Highway 12 onramp closure to northbound 101 had initially been planned for 10 days, but it was feared that weekday commute traffic could suffer delays of up to 90 minutes, Smith said.

Caltrans settled on the weekend closures because traffic is lighter.