County of Marin - News Releases - Traffic Signal Installation

For Immediate Release
June 20, 2016

Updated Signal to be Installed at Busy Intersection

5-light cluster at Tennessee Valley & Shoreline Highway in southern Marin

San Rafael, CA – A busy intersection in an unincorporated area of southern Marin County is getting a new traffic signal head to help ease historically congested conditions, but it’s not the kind of signal head Marin County drivers are used to seeing.

An overhead view of the intersection where the updated traffic signal will be installed.This is the Southern Marin intersection where the updated signal will be installed.
Workers will take down a signal head installed in 2013 at the junction of Tennessee Valley Road and Shoreline Highway (aka Highway 1) and replace it with one that has a cluster of five lights. The lights are arranged with a red stop light on top, two caution yellow lights side by side below the red one and two green lights side by side at the bottom. The yellows and greens will have arrows for those turning left and solid colors for through traffic. Barring unforeseen delays, the new signal head will be installed overnight on June 23.

Drivers on westbound Shoreline Highway making left turns onto southbound Tennessee Valley Road will have a designated left-turn arrow and they will also be permitted to turn left under a solid green light if they yield to oncoming traffic. The improvement will provide additional green time for the traffic making left turns to Tennessee Valley Road and in turn reduce congestion along westbound Shoreline Highway.

The Marin County Department of Public Works (DPW) and the California Department of Transportation (Caltrans) are overseeing the installation by contractor DC Electric, based in Cotati.

“Although this type of traffic signal head has been used at many intersections in California, it has not previously been installed in Marin County,” DPW Principal Civil Engineer Robert Goralka said. “We want to notify drivers about the change and to let them know of the need for drivers to yield to oncoming traffic when making a left turn from Shoreline Highway onto Tennessee Valley Road. If they are turning left on the solid green ball, they should turn only if they have enough space to complete the turn before creating a hazard for an oncoming vehicle, bicyclist or pedestrian.”

Sean Nozzari, Deputy Director of Traffic Operations for Caltrans District 4, said the added signal heads optimize the timing and efficiency of the signal system for all users, including motorists, pedestrians, and bicyclists. “This traffic signal is a good example of state and County resources coming together to help meet the increasing safety and mobility needs in our Bay Area communities,” Nozzari said.

The Tennessee Valley/Shoreline intersection is a critical hub for those who live or work in Tam Valley, Almonte, Mill Valley, Homestead Valley plus the Pacific Ocean beach communities of Muir Beach, Stinson Beach and Bolinas. Drivers headed to Muir Woods National Monument, Mount Tamalpais State Park, the Golden Gate National Recreational Area, the Point Reyes National Seashore and several Marin County Open Space District preserves flow past the Tennessee Valley/Shoreline junction daily.

Together with Tam Junction a quarter mile to the north, the intersection is particularly congested in the summer months. “It’s the gateway to West Marin,” said DPW Assistant Civil Engineer Amanuel Haile. “With school out for the summer, that adds to the daytime traffic.”

Caltrans maintains and operates the traffic signals, including implementation of traffic signal timing for the Shoreline Highway corridor. Caltrans and County DPW are in the process of making signal modifications to reduce traffic delays in the Shoreline Highway corridor. The modifications should be in place by the end of August 2016.


Robert Goralka
Principal Civil Engineer
Public Works

3501 Civic Center Drive.
San Rafael, CA 94903
(415) 473-3076
Email: Robert Goralka
DPW website