Mountain Biking in Marin County: Understanding Risks and Legal Rights

Auto AccidentsBicycle AccidentsMarin County

Sep 30

Photo of a line of bicyclists on a scenic road by the ocean

Published: September 30, 2025. Estimated Read Time: 4 minutes

This article is part of our ongoing series for Auto Accident Awareness Month. (Although we’re covering topics relevant for many types of road-users, including drivers, riders, and walkers!)

So far, we’ve covered topics ranging from California’s comparative fault system, to when you need a lawyer after an accident.

We also looked at the most dangerous California counties for drivers and road-users, and did a deep dive on who decides whether an injury accident is considered “Serious.”

While you’re here, make sure to grab our guide: The Post-Accident Checklist, designed to give you peace of mind should you find yourself in a fender-bender.

Marin County is hallowed ground for mountain biking. From the legendary fire roads of Mount Tamalpais to the technical single-track trails, it's a destination that draws riders from across the globe. The spirit of adventure and connection with nature is what makes riding here so special.

Yet, this incredible terrain also presents significant risks. Many of Marin's most popular routes require cyclists to share narrow, winding roads with motor vehicles before even reaching the trailhead. The consequences of a collision can be devastating.

As both a cherished pastime and a mode of transportation, understanding the unique risks of riding in Marin—and your legal rights if a crash occurs—is not just advisable; it's essential for every cyclist.

The Unique Risks for Mountain Bikers in Marin County

The dangers for mountain bikers in Marin extend beyond the trails themselves. The journey to and from the wilderness often involves navigating a complex and hazardous network of roads.

1. Dangerous Road Designs and High-Speed Corridors

Many of Marin's roads, like the infamous Freitas Parkway in Terra Linda, have a dangerous history. They were originally designed with the intention of being multi-lane highways, resulting in roads that are "far wider than traffic demand warrants, encouraging speeds far faster than is safe" . This creates a deadly environment for cyclists sharing the lane.

2. The "Left-Turn" Intersection Hazard

A specific and tragically common danger is the left-turn collision. This occurs when a driver, attempting to turn left across a lane of traffic, fails to see or yield to an oncoming cyclist traveling downhill.
This exact scenario has played out with heartbreaking frequency. At the intersection of Freitas Parkway and Lea Drive alone, four bicyclists were injured in separate crashes between 2018 and 2023 under identical circumstances before a fatal collision took the life of coach Chris Brignetti in June 2025. In each case, the driver was deemed at fault, yet meaningful safety improvements were delayed.

3. E-Bikes and Changing Trail Access

The rise of e-bikes has introduced new dynamics and safety discussions. Marin County has seen an increase in e-bike related accidents, leading to significant public health attention and even legal challenges over trail access. Furthermore, Marin County has moved forward with a ban on some types of e-bikes for youth riders due to safety concerns, highlighting the evolving nature of cycling risks. Riders must stay informed about local regulations and trail designations, which can change rapidly.

4. Environmental and Visibility Challenges

Marin's natural beauty comes with its own set of hazards. Overgrown foliage in medians can severely limit visibility for drivers, obscuring cyclists from view at critical moments. Furthermore, the same winding roads that provide stunning vistas also feature blind curves and steep drop-offs, leaving little margin for error for both cyclists and drivers.

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Your Legal Rights as a Cyclist in California

Understanding the law is your first line of defense. California law is designed to protect cyclists, but it also assigns responsibilities.

California Bicycle Laws: Key Principles

Same Rights, Same Responsibilities: Bicycles are legally defined as "vehicles" in the California Vehicle Code. This means cyclists have the same right to the road as cars and must also obey all traffic signals and signs.
The Three-Foot Law: Motorists must maintain a minimum distance of three feet when passing a cyclist. A violation of this law is strong evidence of negligence in a collision.
Right-of-Way in Crosswalks and Lanes: A cyclist in a bike lane or crosswalk has the right-of-way. A driver who fails to yield is typically at fault.

Pure Comparative Negligence: What If You're Partially at Fault?

Even if you believe you made a mistake, California's Pure Comparative Negligence law may still allow you to recover damages.

For example:

If a jury finds you were 20% at fault for not signaling a turn and a driver was 80% at fault for speeding, you can still recover 80% of your total damages.
This principle makes it crucial to never admit fault at the scene and to speak with an attorney who can accurately assess the situation.

Read our full article: Understanding California's Comparative Fault Law (What if I'm Partially at Fault?)

What to Do Immediately After a Bicycle Accident

Your actions in the moments following a crash are critical for both your health and any future legal claim.

Seek Medical Attention Immediately: Adrenaline can mask severe injuries. A medical report also creates a vital link between the crash and your injuries. Read our full article: Why You Must See a Doctor After a Car Accident.
Call the Police: A official police report is a crucial piece of evidence. Ensure the officer records your statement and those of any witnesses.
Document Everything: Take photos of the scene, your injuries, your bike, the involved vehicle, and its license plate. Note road conditions, weather, and any obstructed views.
Gather Witness Information: Get the names and contact information of anyone who saw the crash. Their unbiased account can be invaluable.
Do NOT Speak to the Other Driver's Insurance Company: Their goal is to minimize your claim. Do not give a recorded statement without first consulting an attorney.
Preserve Evidence: Keep your damaged bicycle and helmet exactly as they are. Do not have them repaired until they have been fully documented by your attorney.

When a Dangerous Road is to Blame: Government Liability

In cases like the repeated tragedies on Freitas Parkway, the danger may stem from known, dangerous road design. If a city or county was aware of a hazardous condition—through prior crashes, citizen complaints, or their own studies—and failed to take reasonable steps to fix it, they may share liability.
Pursuing a claim against a government entity is a complex process with extremely short, strict filing deadlines (in some cases, you must file a formal claim within six months). This is one of the most critical reasons to immediately consult with an attorney who has experience with these specific claims.

The Critical Role of Uninsured/Underinsured Motorist (UM/UIM) Coverage

Many at-fault drivers are uninsured, underinsured, or may flee the scene (hit-and-run). Your own insurance policy is your primary protection in these scenarios.

UM/UIM coverage is designed to cover your medical bills, lost wages, and pain and suffering when the at-fault driver cannot.
If you own a car, this coverage is likely on your auto policy.
If you don't own a car, you can purchase a non-operator's UM/UIM policy from companies like Progressive, State Farm, or AAA .

This coverage is indispensable for any cyclist in California.

Ride With Confidence, Know Your Rights

Mountain biking in Marin County is a pastime worth protecting. By understanding the risks, advocating for safer roads, and knowing your legal rights, you can help ensure that your passion remains a source of fulfillment, not tragedy.
If you or a loved one has been injured in a bicycle accident on Marin County's roads, our local team has the experience to navigate the unique complexities of your case. We understand the specific dangers of roads like Freitas Parkway and will fight to hold negligent drivers and government entities accountable. Contact us for a free consultation to understand your rights and options.

Sincerely,

The Team at Caldwell Law Firm

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Michael Train Caldwell was born and raised in the San Francisco Bay Area, and resides in Marin County with his two children. The son of renowned San Francisco trial attorney, Edwin Train Caldwell, Michael comes from a family of litigators, and has been representing individuals facing injury and discrimination for over 20 years.