What Is a Road Diet?


by Ken Notis

A road diet is a reduction in the number of through travel lanes on a road, in order to reduce excessive vehicle speeds and improve safety. Often it will involve converting a four-lane road to a three-lane road – the Federal Highway Administration suggests that a three-lane road can handle up to 20,000 vehicles a day. The road diet can make possible adding a center turn lane, pedestrian safety crossing medians, increased distance between motor vehicles and people on sidewalks, bike lanes, and landscaping.

What are its benefits? Road diets change the appearance of a road to drivers, so that they are less likely to drive at unsafe speeds. This results in safer conditions for all road users, particularly pedestrians. With fewer lanes to cross, walking across the street is safer and more comfortable. Combined with center turn lanes, it can also make it easier for a driver to turn onto or off a street. Traffic flow can actually improve, by putting turning drivers in a separate lane, and by reducing speed differentials among vehicles.

Do road diets snarl traffic? When implemented in accordance with Federal Highway Administration guidelines, a road diet has minimal effects on average driver travel times, and can improve safety for drivers. In case after case, the streets impacted by road diets carried the same volumes of motor vehicles.

Is this approach unique to Alexandria? Road diets have been implemented in San Francisco, San Jose, Tampa, New York City, and many other places across the USA. Here in our area, there are road diets in Arlington, Reston, and other parts of Fairfax County. A good example in Alexandria is King Street, between Janneys Lane and Radford Street

Where can I find more information about road diets?

https://safety.fhwa.dot.gov/road_diets/resources/pdf/ fhwasa17021.pdf.