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US 101 and 131

Each day, hundreds of pedestrians walk to or from one of this interchange’s bus stops or between Mill Valley and Strawberry. Recreational, commuter and tourist cyclists travel along the overpass, sharing the outside travel lanes with motorists. Simultaneously, more than 70,000 vehicles use this interchange daily.

TAM, Caltrans, the County of Marin, the City of Mill Valley, the Town of Tiburon, Golden Gate Transit and Marin Transit are working together to develop and evaluate possible future pedestrian and bicycle improvements at the US 101/East Blithedale Avenue-Tiburon Boulevard (Route 131) interchange. These improvements would be implemented over time to enhance access and circulation to the interchange area’s 10 bus stops, walking paths and bicycle routes.

The project’s goals are to identify pedestrian and bicycle improvement measures:

  • Short-term measures that can be implemented in the near-term at reasonable cost without affecting interchange vehicle capacity
  • Medium-term measures that would require moderate traffic operations and/or geometric revisions to the interchange
  • Long-range measures that would require substantial changes to the interchange
Planning Costs
Short-term $1,500,000
Medium-term $10,000,000
Total $11,500,000
Sample Costs:
-short-term pedestrian: $1,000,000
-short-term bicycle: $500,000
-Path + Tunnel: $1,000,000
Squaring up ramps: $3,000,000 - $4,500,000
Widening bridge: $3,500,000