Road Diets Redesigning streets to efficiently move cars as well as people

What Is a Road Diet?

A road diet is a safety-focused roadway alternative that involves narrowing or eliminating travel lanes on an roadway to make more room for other uses or modes—such as walking or biking. The most common type of road diet involves converting an existing four-lane, undivided roadway segment, into three lanes—two through lanes plus a center turn lane. The fourth lane may be converted to a bicycle lane, sidewalk, and/or on-street parking or the space may be reclaimed for other activity-oriented uses.

What Are the Benefits of Road Diets?

Benefits of Road Diets

A Federal Highway Administration (FHWA) policy brief states that a single road diet project can provide safety, operational, and multi-modal benefits. Additionally, adoption of road-diet-related policies and guidance, or Complete Streets policies that support roadway narrowing with multi-modal transportation facilities, can result in widespread advantages:

  1. Improve Safety. According to a FHWA study, converting a road from four to two through lanes with a center can reduce overall crashes by 19 to 47 percent.
  2. Save Money. Road diets can be installed inexpensively, often on existing pavement within the existing right-of-way. When planned in conjunction with a roadway reconstruction or rehabilitation project, a road diet reconfiguration can be achieved essentially for the cost of re-striping pavement lanes.
  3. Increase Multi-Modal Use. Wide-spread road diet implementation can reallocate space for active transportation facilities and increase connectivity among pedestrian-, bicycle-, and public transportation modes and networks.
  4. Increase Quality of Life. Road diets can raise property values, make shared spaces more livable, enhance economic activity in a central business district, and contribute to a community-focused, Complete Streets environment.

What Street Redesign Elements Can Help Calm Traffic?

Traffic Calming Designs

Road Diet example of reducing four vehicle lanes to three, including a turn lane, with additional bike lanes. Photo Credit: FHWA's Road Diet Brochure.

Changing the design of a street can encourage drivers to slow down and remind them that pedestrians and bicyclists are also roadway users. The following design elements can help reduce speeding and reallocate space for other uses:

  1. Facilities for alternate modes of transportation, including bicycle lanes, transit lanes, and bus turnouts
  2. Physical safety barriers, such as curb extensions
  • On-street parking
  • Conversion of on-street parking to a parklet
  • More frequent crossings with signals or stop signs, such as pedestrian refuge islands, raised medians, or mid-block crossing areas
  • Widen sidewalks with active uses like café seating
  • Streetscaping (e.g., trees, sidewalks, landscaping, and pedestrian lighting)

Implementing Road Diets in Delaware

Philadelphia Pike, Claymont

In 2001, the Delaware Department of Transportation (DelDOT) Highway Safety Improvement Program identified the intersection of Harvey Road and Philadelphia Pike in Claymont for safety improvements. During that same time, the community was at the beginning stages of developing a master plan to create economic development opportunities and restore its small town neighborhood atmosphere. DelDOT developed the Claymont Transportation Plan in 2003, not only to address safety issues along Philadelphia Pike, but also to support and enhance a “Claymont Renaissance” initiative.

Philadelphia Pike road diet before and after diagram. Credit: DelDOT Chief Traffic Engineer Mark Luszcz

In 2009, DelDOT requested to conduct a study in order to identify the impacts of a road diet project in Claymont, Delaware. The study identified key intersections that were being underused and would not experience traffic congestion if a road-diet design were implemented. This proposal involved reducing the capacity of a one-mile sector of Philadelphia Pike between Governor Printz Boulevard and Rolling Road.

Before and after images of Philadelphia Pike at Commonwealth Avenue. Photo credit: Urban Engineers

The multi-phase project began in the spring of 2012 and was completed in the following fall, resulting in a “classic” road diet reconfiguration. The one-mile corridor was reduced from a four-lane urban arterial road with 12-foot wide travel lanes, to three 11-foot wide lanes with a center, two-way turn lane. In addition, bike lanes, bike lane buffers, and some on-street parking were installed to calm traffic and improve corridor bikeability. Over the four-year period from 2012 to 2015, there was a 13 percent decrease in accidents, a reduction in speeding, and improved flow of traffic at major intersections.

Image of the Philadelphia Pike corridor, at the Commonwealth Avenue intersection. Photo credit: Urban Engineers

Washington Street Extension, Wilmington

Image of the current traffic flow along Washington Street Extension. Image by: Kyle Grantham, News Journal.

According to DelDOT, the purpose of the Washington Street Extension project is "to create a Complete Street that works well for everyone—people [of all ages and abilities] walking, biking, riding transit, and driving." Washington Street Extension was built as a four-lane divided highway to carry volumes of vehicular traffic that never materialized. About 9,000 vehicles use the street each day, far fewer than the road is designed to carry. For that reason, a road diet is planned to remove one traffic lane in each travel direction. The lanes will be replaced with bike lanes, sidewalks, and on-street parking to make the areas safer for pedestrians and bicyclists traveling to nearby Rockwood Park and Mt. Pleasant High School.

Union Street, Wilmington

A before and after schematic showing plans for a road diet on Union Street. Credit: West Side Grows Together

West Side Grows Together is a network of residents, businesses, institutions, and community groups working together to revitalize local neighborhoods in Wilmington, Del. The coalition hosted a series of annual Better Block events to demonstrate how neighborhood streets could be transformed into walkable, vibrant cultural corridors. Before the project, the corridor dedicated about 90 percent of its space to cars and only 10 percent to people.

West Side Grows Together's Better Block event in 2016 presented the possible redesign of Union Street. Photo Credit: West Side Grows Together

This project began in 2012, when business owners and community members came together to develop a West Side Revitalization Plan. The plan took off in 2014 when a community volunteer group started the Better Block Project, as a temporary take-over of Union Street. The community used a tactical urbanism approach to demonstrate the potential redesign of the busy corridor that lacked a pedestrian-friendly environment. For three days each August, from 2014 to 2017, Better Block participants removed one lane from Union Street's three lanes of one-way traffic. The series of annual community-designed events demonstrated a safer, more engaging pedestrian- and bicycle-friendly area through landscaping, outdoor dining, public art, interactive activities, performance areas, redesigned parking, and a bike lane.

In 2016, West Side Grows Together, the City of Wilmington, DelDOT, and the Wilmington Area Planning Council hosted an on-site public workshop to gain public input on a permanent road diet reconfiguration for Union Street. Based on the success of the multi-year Better Block Program, high levels of community engagement, and favorable public feedback, the new vision of Union Street became a "Re-Stripe Reality" in October 2017. With DelDOT funding support, Union Street's reconfiguration and addition of 20 percent more parking is helping to calm traffic; improve safety for bicyclists, pedestrians, and motorists; and boost economic activity for local businesses.

A Re-Stripe Reality! Credit: West Side Grows Together.

To learn more, visit Complete Streets section of the The Delaware Complete Communities Planning Toolbox.