Signalized Intersections

Technical Assistance & Tools

  • Signalized Intersections: An Informational Guide, FHWA-SA-13-027, July 2013.
    Because traffic signals play an important role in improving safety at intersections, the FHWA produced Signalized Intersections: Informational Guide, which provides methods for evaluating the safety and operations of signalized intersections and tools to remedy deficiencies. The guide includes examples of novel treatments and current best practices by jurisdictions across the United States. These treatments include low-cost measures such as improvements to signal timing and signs, and high-cost measures such as intersection reconstruction or grade separation.

  • FHWA / AASHTO Scan Signalized Intersection Safety, May 10, 2002 through May 26, 2002.
    The international scan visited the United Kingdom, Germany, the Netherlands, and Sweden.  The goals and objectives were to (1) identify promising and readily implementable intersection-safety solutions and/or programs for deployment in the United States; (2) identify and overcome implementation barriers and special needs and (3) gather specific examples and documentation.

  • NCHRP Report 500: Volume 12: A Guide for Reducing Collisions at Signalized Intersections [HTML, PDF 1.62 MB]

  • NEW Proven Safety Countermeasures
    Backplates with Retroreflective Borders are featured as one of the nine Proven Safety Countermeasures that are the subject of the 2012 Guidance Memorandum on Promoting the Implementation of Proven Safety Countermeasures.

  • Traffic Detector Handbook, Volume I, FHWA-HRT-06-108

  • Traffic Detector Handbook, Volume II, FHWA-HRT-06-139

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Active Projects

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  • Professional Development Module: Engineering Intersections to Reduce Red-Light Running
    Red-light running is a complex problem with few simple answers. This one-hour training program emphasizes engineering countermeasures to red-light running. Potential countermeasures discussed in this module address signal visibility and conspicuity, signal timing, increasing the likelihood that drivers will stop and reducing or eliminating the need for stopping. ITE, 2004. CD-ROM. ISBN: 0-935403-85-X.

  • Safety Analysis-Signalized Intersections
    Institute of Transportation Engineers. The course is a guided tutorial that assists transportation professionals in analyzing crash data and identifying appropriate countermeasures to reduce the frequency of crashes and the fatalities, personal injury and property damage involved. Key concepts are explained using an interactive format and reinforced through a case study. Upon completion you’ll be able to:

    • Identify locations for crash studies;
    • Determine data requirements;
    • Construct and interpret a collision diagram;
    • Group crash data and isolate crash types;
    • Identify possible causes; and
    • Recommend viable safety countermeasures.

  • Signalized Intersection Guidebook Workshop, FHWA-NHI-380078

  • Traffic Control Devices-Traffic Signal Needs Determination, Institute of Transportation Engineers. This course is part of the traffic control devices series and has been developed as a guided tutorial to assist staff engineers and technicians in using the methodology outlined in the Manual on Uniform Traffic Control Devices (MUTCD) 2000 for Traffic Control Signal Needs Study. The key concepts underpinning the process of determining signal needs are explained and case studies are used to illustrate the dependent variables. A PDF summary of the course is available for future reference. Upon completion you’ll be able to:

    • Identify steps in a traffic signal needs determination;
    • Collect and analyze traffic data;
    • Determine if warrant conditions are met;
    • Identify the appropriate report requirements;
    • Assemble an engineering study report;
    • Identify the advantages and disadvantages of installing a traffic signal; and
    • Identify alternative improvements.
  • Traffic Signal Design and Operation Training Course, FHWA-NHI-133028

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Program Contact

Jeffrey Shaw


What's New

Signalized Intersections: An Informational Guide

South Carolina Case Study: Systematic Intersection Improvements

Stop-Controlled Intersection Safety: Through Route Activated Warning Systems

Roundabouts: An Informational Guide, Second Edition (NCHRP Report 672)

Roundabouts Peer-to-Peer Assistance

How to drive a roundabout (WSDOT)

Modern Roundabouts: A Safer Choice


FHWA's Intersection Resources Library CD-ROM

Roundabouts Technical Summary

Mini-Roundabouts Technical Summary

Access Management in the Vicinity of Intersections Technical Summary

Intersection Safety Case Studies

Intersection Safety Technologies

Presentation: Intersection Safety

Example Intersection Safety Implementation Plan

Intersection Safety Implementation Plan Workshop

Example Data Analysis Package and Straw Man Outline