California Car Collision Rates Decline After Shelter-in-Place Mandates

A hopeful forecast predicts that thousands of monthly traffic collisions will be avoided due to reduced vehicular travel during California’s shelter-in-place period.

1 minute read

April 9, 2020, 9:00 AM PDT

By Lee Flannery @leecflannery


Cars

Alexey Rotanov / Shutterstock

A U.C. Davis survey finds that auto collisions have been curbed by more than 50 percent since the stay-at-home orders went into effect around the state of California in March. "The survey suggests that a 60% drop in traffic volume — when compared with the same period last year — accounts for a roughly 50% decline in collisions on roadways policed by California Highway Patrol," writes Louis Sahagun. 

The U.C. Davis Road Ecology Center's "California Highway Incident Processing System," which tracks close to real-time traffic data in California, reported only 500 collisions in the period between March 21st and March 30th, a significant reduction from the 1,116 collisions observed in the ten-day period between March 10th and March 19th. The decrease in vehicle travel and traffic volume resulting from the state-wide order also correlates to a reduction in fatality and injury caused by collisions. 

Road Ecology Center co-director Fraser Shilling was unable to assess animal fatalities on public roadways, the main focus of his research, due to the lack of data in the short time period. Shilling hopes to center future research on "cost-savings and other social benefits from reduced injuries and deaths on state highways due to COVID-19."

Wednesday, April 1, 2020 in Los Angeles Times

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Cover CM Credits, Earn Certificates, Push Your Career Forward

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

June 11, 2025 - Diana Ionescu

Metrorail train pulling into newly opened subterranean station in Washington, D.C. with crowd on platform taking photos.

Congressman Proposes Bill to Rename DC Metro “Trump Train”

The Make Autorail Great Again Act would withhold federal funding to the system until the Washington Metropolitan Area Transit Authority (WMATA), rebrands as the Washington Metropolitan Authority for Greater Access (WMAGA).

June 2, 2025 - The Hill

Large crowd on street in San Francisco, California during Oktoberfest festival.

The Simple Legislative Tool Transforming Vacant Downtowns

In California, Michigan and Georgia, an easy win is bringing dollars — and delight — back to city centers.

June 2, 2025 - Robbie Silver

Color-coded map of labor & delivery departments and losses in United States.

The States Losing Rural Delivery Rooms at an Alarming Pace

In some states, as few as 9% of rural hospitals still deliver babies. As a result, rising pre-term births, no adequate pre-term care and "harrowing" close calls are a growing reality.

June 15 - Maine Morning Star

Street scene in Kathmandu, Nepal with yellow minibuses and other traffic.

The Small South Asian Republic Going all in on EVs

Thanks to one simple policy change less than five years ago, 65% of new cars in this Himalayan country are now electric.

June 15 - Fast Company

Bike lane in Washington D.C. protected by low concrete barriers.

DC Backpedals on Bike Lane Protection, Swaps Barriers for Paint

Citing aesthetic concerns, the city is removing the concrete barriers and flexposts that once separated Arizona Avenue cyclists from motor vehicles.

June 15 - The Washington Post