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MENLO PARK, San Mateo County, Calif., Nov. 6, 2026 — A four-vehicle crash blocked lanes on northbound US 101 near the Willow Road off-ramp on Wednesday afternoon, November 4, according to the California Highway Patrol. At least one ambulance was requested for a reported injury, per the CHP incident log.
The crash was reported just before 3:40 p.m. near the US 101/Willow Road interchange in Menlo Park, according to the CHP. The log describes a white Tesla sedan, a gray Infiniti SUV, a blue Tesla Model 3 and a Toyota involved in the collision, with three of the vehicles blocking lanes 4 and 5 on the right side of the freeway.
The CHP log initially listed the call as a collision with unknown injuries before it was updated to reflect that an ambulance had been requested, indicating at least one person was hurt. The extent of that injury has not been released. A driver of a gray Nissan Altima reportedly stopped to assist and told responders she was unable to merge back onto the freeway to continue on her route, per the log.
No additional details on the cause of the crash, possible impairment, or the number of people hurt have been released. The CHP has not said whether the roadway has since reopened. The incident remains under investigation.
We hope everyone involved is okay, and we will share more as details are confirmed.
Intersection Safety in California
The multi-vehicle crash was reported at US-101 and Willow Road in Menlo Park. Readers following crash news in San Mateo County can find more about intersections across the state on our guide to California intersections.
Frequently Asked Questions
How does low visibility or glare contribute to multi-vehicle pile-ups?
Even brief drops in visibility, from sun glare, fog or heavy traffic, can cut the time drivers have to react, making it harder to stop before hitting a slowed or stopped vehicle ahead.
Why does following distance matter so much in freeway traffic?
A longer gap between vehicles gives drivers more time to brake if traffic ahead slows suddenly, which is usually the difference between a near-miss and a chain-reaction crash.
Are secondary crashes common after an initial wreck on a freeway?
Yes. Vehicles slowing or stopping near the scene of an earlier crash create a hazard for oncoming traffic, which is why responders usually work quickly to move disabled vehicles out of travel lanes.
What makes investigating a multi-vehicle crash more complicated?
With several vehicles involved, investigators usually have to determine the sequence of impacts and how each vehicle came to a stop, which can take longer than a two-vehicle collision.
