Case Studies: Road Diets

These items focus on the two "E"s of traffic safety—Enforcement and Engineering—associated with increasing the safety of walking and bicycling.

Under the Walk Bike More tab, you will find items that focus on the two other "E"s—Education and Encouragement.


Road Diets

Road Diets: Case Studies Presented in Slide

A presentation by Michael Ronkin.

Federal Highway Administration Evaluation of "Road Diets"

This Highway Safety Information System (HSIS) summary replaces an earlier one, Evaluation of Lane Reduction “Road Diet” Measures and Their Effects on Crashes and Injuries (FHWA-HRT-04-082), describing an evaluation of “road diet” treatments in Washington and California cities. This summary reexamines those data using more advanced study techniques and adds an analysis of road diet sites in smaller urban communities in Iowa.

Road Diet (Roadway Reconfiguration)

The classic roadway reconfiguration, commonly referred to as a "road diet," involves converting an undivided four lane roadway into three lanes made up of two through lanes and a center two-way left turn lane. The reduction of lanes allows the roadway to be reallocated for other uses such as bike lanes, pedestrian crossing islands, and/or parking. Road diets have multiple safety and operational benefits for vehicles as well as pedestrians

Longfellow Street Shared Space Design

The design raises Longfellow and adjacent streets to sidewalk level. Paving materials, textures, tones, and colors guide users’ movements. Gardens are expanded and made more sustainable with drought resistant landscaping, rain gardens, and permeable pavers. Pedestrian solar lighting and colored paving at the intersections create a neighborhood entrance. A narrow carriageway calms traffic and mitigates infringement from non-local traffic. —from information sheet by Nelson\Nygaard for City of Santa Monica

Separated Bikeway (City of Long Beach

By moving the parking lane away from the curb and installing temporary or pemanent separators, a bikeway can be protected from motorized traffic, and conflicts between bicyclists and parked cars are eliminated.

Striping to create road space for bicycles

Road diets or simply restriping wide lanes with bike lanes improves bicycle access and has overall safety benefits. (From: Complete Intersections: A Guide to Reconstructing Intersections and Interchanges for Pedestrians and Bicyclists, Draft 2010 prepared by Caltrans, Alta Planning + Design, Cambridge Systematics.)

Road diet before and after

Road diets re-purpose existing roadway space to make it more attractive to more types of users. (Photos courtesy California Department of Transportation Office of Community Planning.)

VTA Bicycle Technical Guidelines: Woonerf/Shared Street

The Santa Clara County Valley Transportation Authority (VTA) sponsored a design competition in summer 2012 for woonerfs and bicycle corrals. The technical guidelines are available here. Links to other resources can be found at the VTA Bicycle Program page.

Walkable 101: Road Diets

Dan Burden from the Walkable and Livable Communities Institute shares the how to use road diets to increase walkability in a community.

Moving Beyond the Automobile: Road Diets

In this film from StreetFilms, road diets are explained.