The ‘Quiet Roundabout Revolution’ Sweeping U.S. Cities

Roundabouts, which can dramatically improve traffic safety, have been slowly proliferating across U.S. cities over the last two decades.

1 minute read

December 5, 2022, 12:07 PM PST

By Diana Ionescu @aworkoffiction


Roundabout

Malota / Shutterstock

Although a lack of federal data makes it difficult to evaluate the scale of their growth, roundabouts and traffic circles are slowly but surely making their way into American cities, writes Andrew Van Dam in the Washington Post.

According to Lee Rodegerdts, who literally wrote the book on roundabouts—Roundabouts: An Informational Guide—there are now roughly 9,000 roundabouts around the country, plus over 160 rotaries and more than 700 traffic-calming circles.

Florida boasts the most roundabouts, but it also has the third-largest population in the nation. Nebraska has the most roundabouts per person, but they’re spread across one of the sparsest (and often most scenic) road networks in the country. Per mile of road, Maryland actually emerges as the roundabout champion.

As far as cities go, the wealthy enclave of Carmel, just outside Indianapolis, has more roundabouts than any other U.S. locality thanks to its long-term mayor, who has championed roundabouts for decades. Carmel has built more than 140 roundabouts under his tenure.

“Why add a roundabout, you might ask. Because roundabouts offer impressive safety gains. In general, a roundabout will drive down fatal crashes by 90 percent and cut all car-crash injuries by at least 75 percent, even while accommodating a higher volume of cars.” The benefit is even greater at rural two-way stops, cutting traffic injuries by as much as 90 percent.

Monday, December 5, 2022 in The Washington Post

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

Aerial view of town of Wailuku in Maui, Hawaii with mountains in background against cloudy sunset sky.

Maui's Vacation Rental Debate Turns Ugly

Verbal attacks, misinformation campaigns and fistfights plague a high-stakes debate to convert thousands of vacation rentals into long-term housing.

July 1, 2025 - Honolulu Civil Beat

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.

July 2, 2025 - Diana Ionescu

White and purple sign for Slow Street in San Francisco, California with people crossing crosswalk.

San Francisco Suspends Traffic Calming Amidst Record Deaths

Citing “a challenging fiscal landscape,” the city will cease the program on the heels of 42 traffic deaths, including 24 pedestrians.

July 1, 2025 - KQED

Google street view of red brick multi-story power plant building in Pittsburgh, PA.

Defunct Pittsburgh Power Plant to Become Residential Tower

A decommissioned steam heat plant will be redeveloped into almost 100 affordable housing units.

July 4 - Pittsburgh Post-Gazette

Cyclist on protected bike lane in middle of street in Washington D.C. with Washington Monument obelisk visible in background.

Trump Prompts Restructuring of Transportation Research Board in “Unprecedented Overreach”

The TRB has eliminated more than half of its committees including those focused on climate, equity, and cities.

July 4 - Streetsblog USA

Blue and silver Amtrak train at small station.

Amtrak Rolls Out New Orleans to Alabama “Mardi Gras” Train

The new service will operate morning and evening departures between Mobile and New Orleans.

July 3 - New Orleans City Business