Work Begins on Bellam Boulevard US-101 and I-580 Ramps

This is a joint news release by the Marin County Department of Public Works and the Transportation Authority of Marin (TAM)

For Immediate Release –

Marin County, CA –

TAM-led project to alleviate traffic congestion will require nighttime closures

Marin County, CA – The Bellam Boulevard US-101 off-ramps improvement project is set to begin construction on Monday, March 10, in San Rafael. The project is intended to reduce the traffic congestion by improving the Bellam Boulevard ramps on northbound US-101 and eastbound I-580.

The work includes adding a second lane to the off-ramp and adding a right turn lane to Bellam Boulevard to improve traffic flow, turn movements, and merging.  Construction is expected be completed this winter. The construction will require intermittent nighttime closures of the ramps.

The $8.1 million project is led by the Transportation Authority of Marin (TAM) and is being conducted on state highway property, which is owned and operated by the California Department of Transportation (Caltrans). TAM designed and funded the project and has partnered with County of Marin Department of Public Works (DPW) to administer the construction phase of the project.

Work will begin on Monday, March 10, with the placement of temporary barriers, known as K-rail, on the right shoulder of the northbound US-101 Bellam Boulevard off-ramp. While the number of traffic lanes available to motorists will not be limited by the K-rail, it is anticipated that the construction activities behind the barrier may result in traffic delays caused by the natural response of drivers passing through a construction zone.

The effort will require periodic closures of the Bellam Boulevard ramps. The closures are planned to only take place between midnight and 5 AM. Currently, no ramp closures are anticipated during daytime hours. The first set of nighttime closures will be from March 10 through March 14, and detours will be in place. A traffic advisory was issued on March 5 in English and Spanish.

All project adjustments and closures require approval from Caltrans before being implemented and public outreach would be made to notify residents. On location signage will be posted in advance to alert motorists of upcoming closures and detours will be in place as needed.

The project entails widening the Bellam Boulevard northbound US-101 off-ramp, separating the traffic turning left from the traffic turning right or continuing straight across the intersection onto the eastbound I-580 on-ramp. Once the project is complete, which is expected to be sometime this winter, the improvements are expected to reduce traffic congestion on the ramps and provide an immediate benefit to drivers.