Marin County transit agency exploring bus use of Highway 101 shoulder during commute

A Marin County transportation agency is exploring the use of Highway 101 shoulders to allow mass transit to skirt slow or stopped traffic during commute hours.|

Few morning-drive commuters associate southbound U.S. Highway 101 with speed.

But that’s precisely what North Bay transportation officials hope motorists will gain in launching a study to examine allowing bus traffic on 101 to ride on the shoulder between Novato and San Rafael from Atherton to Mission Avenue exits, respectively.

Through the years, those sections have been known for traffic clogs as many commuters traveling from Marin County to San Francisco end up there like clockwork each morning.


If it’s deemed safe for bus traffic to bypass vehicles in the lanes, the Transportation Authority of Marin plans to target the time slot between 6:30 a.m. and 9 a.m.

TAM Planning Manager Derek McGill told the Business Journal the bottlenecks occur between those hours “pretty consistently.” Shoulder-riding buses in the northbound side would not be permitted in the afternoons, since the shoulder is narrower.

“We have to improve our transit service. That’s our regional goal,” McGill said. “This is just one tool in our toolkit.”

The $308,000 study from Kimley-Horn, the engineering firm tasked with completing it, is due next summer.

Marin’s transportation agency will examine whether allowing buses to ride in the part time transit lane at up to 35 miles per hour will take some of the burden off the travel lanes.

Granted, McGill admitted that traffic on the 101 has been reduced by 20% from the Golden Gate Bridge toll plaza, since the pandemic began but more vehicles are expected to use the highway when office workers return to a pre-COVID-19 state. An average 200,000-plus vehicles traveled on 101 daily in 2019. And southbound morning congestion along the 101 corridor is expected to grow, the agency contends.

“The interesting thing is we’re still getting considerable traffic (despite shelter-in-place orders and prevalent remote work),” McGill said.

TAM planners believe remote workers are still out and about as well as delivery drivers in great numbers during the period of the pandemic.

“Turning the shoulders into part time transit lanes would be a relatively quick project to implement to provide travel time savings for transit riders,” TAM Executive Director Anne Richman said in a statement. “It will add freeway capacity without having to add new lanes, which is not feasible in northern Marin.”

Caltrans’ Sacramento headquarters and district office collectively responded to the Business Journal’s inquiry by saying it will review the study based on safety issues including those in which public vehicles responding to incidents are needing to use the shoulder.

TAM has pledged to have its dispatch center notify the bus drivers when there are sig alerts and other problems.

The study’s concept was met with optimism from the Metropolitan Transportation Authority, which plans, finances and coordinates transit options for the San Francisco Bay Area’s nine counties.

“As folks return to pre-pandemic travel patterns, it’s important that transit be as attractive an alternative as it can be,” MTC spokesman John Goodwin said.

In other Highway 101 news, the stretch referred to as the “Marin-Sonoma Narrows” just received $40 million additional funding to improve six miles of the roadway between Novato and Petaluma. Bottlenecks often occur where four lanes merge into three.

A few years in the making, the total 17-mile project cost more than $762 million to add more carpool and bicycle lanes.

Susan Wood covers law, cannabis, production and transportation as well as banking and finance. For 25 years, Susan has worked for a variety of publications including the North County Times in San Diego County, Tahoe Daily Tribune and Lake Tahoe News. She graduated from Fullerton College. Reach her at 530-545-8662 or

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