USA Banner
  U.S. flag
              An official website of the United States government Here's how you knowOfficial US Government Icon
              **Official websites use .gov**A **.gov** website belongs to an official government organization in the United States.
            Secure Site Icon
              **Secure .gov websites use HTTPS**
                  A **lock** ( A locked padlock ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. 
 U.S. Department of Transportation Icon United States Department of Transportation
 Search DOT
            Search
                    About FHWAFHWA Organization
                Headquarters Offices
                Field Offices
                Strategic Plan
                Business Opportunities
                Staff Directories
                Careers
                Highway History
                Contact UsProgramsAcquisition Management
                Civil Rights
                Federal Lands Highway
                Infrastructure
                Innovative Program Delivery
                Operations
                Planning, Environment, and Realty
                Policy
                Research, Development, and Technology
                Safety
                Browse by TopicsResourcesCore Highway Topics
                Federal Aid Essentials
                Automation
                Complete Streets
                Laws and Regulations
                Policy & Guidance Center
                Section 508
                Publications and Statistics
                Professional Development
                National Highway Institute
                Resource Center
                Accessibility Resource Library
                FHWA Research LibraryNewsroomPress Releases
                Speeches & Testimony
                Photos
                Videos
                Media ContactsMenu FHWA Highway Safety Programs Home
                        Safety
                        Proven Safety Countermeasures


            
            In This Section
        Proven Safety Countermeasures
                Search Safety Proven Countermeasures
                Resources
      
   Related Links
          For More Info Visit the Office of Safety's Road Diet website

              Road Diets (Roadway Reconfiguration)
U.S. Department of Transportation logoU.S. Department of Transportation
    Federal Highway Administration
    FHWA-SA-21-046

          PDFRoad Diets_508.pdf (PDF, 558.1 KB)


        

A Road Diet, or roadway reconfiguration, can improve safety, calm traffic, provide better mobility and access for all road users, and enhance overall quality of life. A Road Diet typically involves converting an existing four-lane undivided roadway to a three-lane roadway consisting of two through lanes and a center two-way left-turn lane (TWLTL).

"This illustration shows the configuration of a roadway before and after a road diet. The left side of the illustration shows a four-lane undivided highway, marked by a double yellow centerline, solid white edge lines, and dashed white lines distinguishing lanes of travel in the same direction. Four white arrows indicate the direction of travel for each lane, with the two right-most arrows pointing upward in the image and the two left-most arrows pointing downward. The right side of the illustration shows a three-lane highway with a two-way left turn lane in its center. The two way left turn lane is delineated by double yellow lines that are dashed on the inside of the two way left turn lane and solid on the outside of the two way left turn lane. The edge of the general travel lanes are delineated by a solid white edge line. Outside of the general travel lanes are bike lanes marked with a bicycle symbol and directional arrow. Together, the three-lane roadway with adjacent bike lanes occupy the same width of pavement as the previous four-lane undivided highway."

**Before and after example of a Road Diet.**Source: FHWA

**Benefits of Road Diet installations may include:**

Reduction of rear-end and left-turn crashes due to the dedicated left-turn lane.
	Reduced right-angle crashes as side street motorists cross three versus four travel lanes.
	Fewer lanes for pedestrians to cross.
	Opportunity to install pedestrian refuge islands, bicycle lanes, on-street parking, or transit stops.
	Traffic calming and more consistent speeds.
	A more community-focused, Complete Streets environment that better accommodates the needs of all road users.A Road Diet can be a low-cost safety solution when planned in conjunction with a simple pavement overlay, and the reconfiguration can be accomplished at no additional cost. Typically, a Road Diet is implemented on a roadway with a current and future average daily traffic of 25,000 or less.

        Sources
        1. (CMF ID: 5554, 2841) *Evaluation of Lane Reduction ”Road Diet“ Measures on Crashes*, FHWA-HRT-10-053, (2010).
    
    Safety Benefit IconSafety Benefits:
              
4-Lane to 3-Lane, Road Diet Conversions
          19-47%
      
            reduction in total crashes.1



**Road Diet project in Honolulu, Hawaii.**
Source: Leidos U.S. DEPARTMENT OF TRANSPORTATION

**Federal Highway Administration**

1200 NEW JERSEY AVENUE, SE

WASHINGTON, DC 20590

202-366-4000Subscribe to email updates
                    About
  

        
              About FHWA
                Careers
                Org Chart
                Staff Directories
                Work with UsPrograms
  

        
              Acquisition Management
                Civil Rights
                Federal Lands Highway
                Infrastructure
                Innovative Program Delivery
                Operations
                Planning, Environment, and Realty
                Policy
                Research, Development, and Technology
                SafetyPolicies, Rights, Legal
  

        
              About DOT
                Accessibility
                Budget and Performance
                Civil Rights
                FOIA
                Information Quality
                No FEAR Act
                Office of Inspector General
                Privacy Policy
                USA.gov
                Web Policies and Notices
                Web StandardsNews & Events
  

        
              Newsroom
                Press Releases
                Speeches & Testimony
                Media Contacts
                Connect with Us