News Changes Coming to the US 101 Crossing in Corte Madera

Caltrans is planning upgrades to the US-101/Tamalpais Drive freeway ramps (called an “interchange”) in Corte Madera. This represents a substantial opportunity to improve access for people of all ages and abilities walking and biking in Central Marin. Find out how you can help advocate for a safe Corte Madera 101 crossing.

See below for a summary of upcoming meetings and how to submit your comment about the need for a safe bikeway separate from high-speed traffic.  


Monday, August 8, 6:30 – 8 PM: Special Meeting of the Corte Madera Bicycle Pedestrian Advisory Committee (Zoom link here)

Tuesday, August 16, 6:30 PM: Presentation from Caltrans at Corte Madera Town Council (Zoom link here)

SUBmIT COMMENT on caltrans Environmental Document

Comments on the project can be submitted until Monday, August 22nd. Click here for MCBC’s comment template. Alternatively, you can submit your own comments to If you want to dig into the document itself, you can find that here.

Project Background

As every resident of Marin knows, US-101 is the primary north-south route through the county. And as anyone who rides bikes in Marin knows, that highway acts as a massive barrier to east-west travel for people walking or biking. A crossing through a Caltrans-owned freeway interchange is typically one of the most harrowing parts of any ride, full of speeding cars, roadway debris, and often not much more than a hint of a bike lane. 

Corte Madera 101 Crossing

Crossings of US-101 are typically so hairy that many riders avoid freeway interchanges altogether, opting to travel out of their way to a street that doesn’t intersect with the freeway (like Wornum Way), or simply choosing to get in the car and drive. Many folks who might endure a crossing themselves wouldn’t send their 7th grader to school across one.

Because of these issues, opportunities to reconstruct a freeway interchange in Marin can be potentially transformative projects, knitting together a community divided by the freeway-building era of the 20th century. We currently have such an opportunity at the interchange in Corte Madera, where Tamalpais Drive crosses US-101. 

In July, Caltrans announced several alternatives to reconfigure the interchange that separates east and west Corte Madera, and sits between the Town Center and the Village. The crossing, as it stands, presents many problems for users outside of a car. Bicyclists have to ride in a narrow shoulder, pedestrians and bicyclists have to pass through several “uncontrolled” on and off ramps, the steep spiral ramps are not compliant with the Americans with Disabilities Act, and there isn’t even a sidewalk on the north side of the structure!

The upcoming project has the potential to address some (or all) of these issues, depending on which alternative Caltrans selects. Until August 22nd, members of the public have an opportunity to comment on the designs and express their needs and preferences.  

Project Alternatives

Corte Madera 101 Crossing

Concept view of one of the alternatives

Caltrans is considering six different alternatives (see 3D renderings of the alternatives here). The differences are somewhat complex (and have been explained well in this presentation from our friends at WTB-TAM), but it boils down to this: 

  • Alternatives 2A/2B do the bare minimum for pedestrians and do not improve the experience for people riding bikes
  • Alternatives 3A/3B and 4A/4B substantially improve the experience for people on bikes by providing shared use paths to separate riders from high-speed car traffic. 
  • 4B is our preferred alternative, but all of the alternatives except 2A/2B would suffice.

What You Can Do

See the links above for the upcoming meetings on the Corte Madera 101 crossing project. Attend any or all and voice your strong support for separating bicycle and car traffic and removing uncontrolled freeway ramps, which are dangerous for people who walk and bike. 

You can write your own letter to or use the MCBC template. Don’t wait, because the deadline is Monday, August 22nd. 

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