Understanding Road Diets

An explainer from Momentum Magazine outlines the benefits of road diets, a popular but controversial traffic calming strategy that focuses on reducing the number of vehicle lanes and adding sidewalks and other bike and pedestrian infrastructure to streets.

According to author Ron Johnson, “ The first road diet in the United States was implemented in 1979 in Billings, Montana. Since then, cities like Charlotte, Chicago, San Francisco, and New York have all embraced the model. But it’s not just a design trend—road diets are backed by powerful data and safety results.”

Reducing the number of lanes and average speeds can cut crashes by as much as 52 percent, and slower speeds also mean crashes can be less serious when they do occur.

Although road diet opponents worry about traffic, “Removing travel lanes can actually lead to a reduction in overall vehicle trips—a phenomenon known as traffic evaporation. Some drivers shift to alternative routes or, increasingly, to alternative modes of transport.” Better bike and pedestrian infrastructure incentivizes more people to use those modes, and bus lanes make transit a more reliable option. Road diets thus also lead to reduced carbon emissions and cleaner air. 

“As our cities continue to evolve, road diets offer a cost-effective, data-backed, and scalable way to make them safer, cleaner, and more livable,” Johnson concludes.