Ramp metering at four Marin sites along US-101 set to start June 24

Caltrans is scheduled to activate four ramp meters along Northbound US-101 in Marin County on Tuesday, June 24 to help ease traffic along the highway.

To address the congestion and safety concerns on US 101, the Metropolitan Transportation Commission worked with Caltrans and the Transportation Authority of Marin to evaluate the feasibility of implementing ramp metering along northbound US 101 corridor in southern Marin County.

Ramp metering is a traffic management strategy that uses traffic signals on freeway on-ramps to control the rate at which vehicles enter the freeway. By creating room between vehicles, ramp meters reduce congestion, enhance safety, and improve overall traffic flow.

During ramp metering hours at the specific on-ramps, motorists will encounter active ramp metering signals that cycle to manage vehicle flow. Advance warning signs at these metered on-ramps will also be activated simultaneously to alert drivers.

These four ramps will be activated in Marin:

• Bridgeway/Gate 6 Road diagonal on-ramp
• Eastbound Tiburon Boulevard/SR-131 loop on-ramp
• Westbound Tiburon Boulevard/SR-131 diagonal on-ramp
• Westbound Tamalpais Drive diagonal on-ramp

These ramp meters are located in the cities of Sausalito, Mill Valley and Corte Madera where traffic bottlenecks have been identified. Metering signals will be active Mondays through Fridays from 2 p.m. until 7 p.m. each day.

The ramp metering operations will help reduce traffic congestion and delays, enhance safety and improve the efficiency and reliability of commuter traffic along the corridor.

This activation marks the first phase of the broader ramp metering initiative planned for US-101 in Marin County. As funding becomes available, additional ramp meters are expected to be implemented on both the northbound and southbound directions.