Ecocity Snapshots

The Skinny of Safer Street

Skinny travel lanes create wider sidewalks in downtown Los Angeles.
Written by Rick Pruetz

by Rick Pruetz, Vice President, Ecocity Builders

Over 7,500 pedestrians in the United States were killed by cars in 2022. We no longer call these tragedies an accident. Street design itself often poses an ongoing threat to children, the disabled, the elderly, and anyone else who walks or bikes.

Public officials can be reluctant to follow the commonsense standards of the Complete Streets movement for fear of running afoul of motorists accustomed to dominating the public right of way. However, a new study documents that wide travel lanes encourage speeding and generate more crashes than skinny lanes. Putting fat lanes on a diet produces greater safety while also creating opportunities to create bikeways, transit-only lanes, and wider sidewalks.

The study, from Johns Hopkins University, found that skinny travel lanes improve traffic safety on roadways with speed limits of 35 miles per hour or less. This news comes at a time when pedestrian deaths are the highest in four decades and when biking fatalities increased 44 percent between 2010 and 2020. Proof that these deaths are preventable comes from Europe which experiences from 1.3 to 3.2 pedestrian and cyclist deaths per 100,000 population. In comparison, pedestrian and cyclist fatalities in the US stand at 11.66 per 100,000, almost ten times higher than in Europe.  

Specifically, this research concludes that reducing lanes that are sometimes 13 or more feet in width to nine or ten feet is not only possible but beneficial in the effort to address the ongoing traffic-fatality epidemic. The Johns Hopkins study adds that skinny travel lanes allow communities to create greater equity in the distribution of the public right of way through the addition of bike lanes and wider sidewalks capable of supporting shade-giving street trees. As additional benefits, skinny lanes cost less to build and maintain. Also, with less hardscape, skinny lanes reduce the amount of impervious surface coverage that contributes to flooding and exacerbates urban heat islands.

Elected officials are reluctant to do anything that might slow down cars for fear of retaliation from entitled motorists. A petition drive to recall a member of the Los Angeles City Council was launched in 2017 over roadway narrowing in his district. That road diet was authorized by the city’s 2015 Mobility Plan, which called for the gradual implementation of Complete Streets guidelines. Although the recall petition failed to gather enough support, the threat of recall may explain why Los Angeles has accomplished only five percent of the planned improvements in the almost ten years since the Mobility Plan was adopted. (A notable exception has been downtown LA, where the narrowing of travel lanes has facilitated the installation of bike lanes and wider sidewalks.) 

In 2024, the electorate of Los Angeles forced their elected officials to deliver the roadway equity promised by the 2015 plan. By an almost two-thirds majority, LA voters approved Measure HLA which requires the city to install in the next 10 to 15 years 500 miles of pedestrian improvements, 300 miles of bus-only lanes, and 800 miles of new bike lanes, of which 400 miles would be protected bike lanes.

Other cities are studying this approach. The John Hopkins study should give public officials support for adopting street configurations that promote safety while creating more equitable, planet-friendly, and livable cities. 


Depaolis, J. 2024. The Path to Safety: How Road Diets Can Save Lives: A comprehensive new study shows that narrowing lanes may curb fatalities, save money, promote walking and biking, and mitigate urban heat. Planning Magazine. Chicago: American Planning Association.

Hamidi, S., et. al.. 2023. A National Investigation on the Impacts of Lane Width on Traffic Safety: Narrowing Travel Lanes as an Opportunity to Promote Biking and Pedestrian Facilities Within the Existing Roadway Infrastructure. Johns Hopkins University. JHU-2023-Narrowing-Travel-Lanes-Report.pdf

Narrower Traffic Lanes in Cities Could Help Lower Risk of Traffic-Related Collisions | Johns Hopkins | Bloomberg School of Public Health (

Schneider, B. March 13, 2024. LA Votes for Bike, Bus, and Pedestrian Fixes as Traffic Deaths Rise. Bloomberg City Lab. Accessed at Why Car-Centric LA Voted to Make Room for Bikes and Buses – Bloomberg

About the author

Rick Pruetz

Rick Pruetz, FAICP, is Vice President of the Ecocity Builders Board and an urban planner who writes about sustainability, most recently Ecocity Snapshots: Learning from Europe’s Greenest Places and Smart Climate Action through Transfer of Development Rights.

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