Improve Traffic: Let Your Car Drive

A new study concludes that many traffic jams could be prevented if onein five vehicles on the road used new adaptive cruise-control.

1 minute read

August 1, 2004, 7:00 AM PDT

By Chris Steins @planetizen


"Synchronized flow is, in physics-speak, in unstable equilibrium: The slightest change, such as a driver changing lanes and forcing others to brake, tips the system into a new state. The result is stop-and-go traffic, a true jam.Physicists are exploring whether adaptive cruise control can prevent this. In ACC, a radar sensor gauges the distance between cars, automatically adjusting speed to maintain a safe distance. Because ACC, which has become standard on some luxury vehicles, can adapt instantly if the lead car brakes (humans take about 0.75 second to react), cars can tailgate safely. ACC can therefore pack more cars into a mile of highway, increasing a road's de facto capacity."

[Editor's note: The link below is available to non-subscribers for a period of 6 days.]

Thanks to Chris Steins

Saturday, July 31, 2004 in Wall St. Journal

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.

4 hours ago - Diana Ionescu

Rendering of Shirley Chisholm Village four-story housing development with person biking in front.

San Francisco's School District Spent $105M To Build Affordable Housing for Teachers — And That's Just the Beginning

SFUSD joins a growing list of school districts using their land holdings to address housing affordability challenges faced by their own employees.

June 8, 2025 - Fast Company

Yellow single-seat Japanese electric vehicle drivign down road.

The Tiny, Adorable $7,000 Car Turning Japan Onto EVs

The single seat Mibot charges from a regular plug as quickly as an iPad, and is about half the price of an average EV.

June 6, 2025 - PC Magazine

SMall backyard cottage ADU in San Diego, California.

San Diego Votes to Rein in “Towering” ADUs

City council voted to limit the number of units in accessory buildings to six — after confronting backyard developments of up to 100 units behind a single family home.

4 hours ago - NBC San Diego

Large tower under construction with crane with American and Texas flags in downtown Austin, Texas against sunset sky.

Texas Legislature’s Surprising Pro-Housing Swing

Smaller homes on smaller lots, office to apartment conversions, and 40% less say for NIMBYs, vote state lawmakers.

5 hours ago - The Texas Tribune

Red brick five-story multifamily housing building in Edmonton, Alberta, Canada.

Even Edmonton Wants Single Staircase Buildings

Canada's second most affordable major city joins those angling to nix the requirement for two staircases in multi-family buildings.

6 hours ago - Canadian Broadcasting Corporation (CBC)