USA Banner

Official 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 ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation
FHWA Highway Safety Programs

Tools and Technology

  • The Highway Safety Manual (HSM)
    A new generation of highway safety analysis tools is being deployed to the transportation community through several innovative research efforts. The Highway Safety Manual (HSM), which will be published as an American Association of State Highway Transportation Officials (AASHTO) document, and supporting implementation tools including SafetyAnalyst, Interactive Highway Safety Design Model (IHSDM), and the Crash Modification Factors (CMF) Clearinghouse were developed by cooperative research initiated by Federal Highway Administration (FHWA). These tools will greatly advance state and local highway agencies’ ability to incorporate explicit, quantitative consideration of safety into their planning and project development decision making.

    The first edition of the HSM provides the best factual information and tools in a useful form to facilitate roadway planning, design, operations, and maintenance decisions based on precise consideration of their safety consequences. The primary focus of the HSM is the introduction and development of analytical tools for predicting the impact of transportation project and program decisions on road safety.

  • AASHTOWare Safety
    Provides state-of-the-art analytical tools for use in the decision-making process to identify and manage a systemwide program of site-specific improvements to enhance highway safety by cost-effective means.

  • Crash Reduction Factors
    This is the percentage crash reduction that might be expected after implementing a given countermeasure at a specific site.

  • Red Light Cameras
    This two-page fact sheet provides an overview of the three types of cameras most often used for red light enforcement.

  • Interactive Highway Safety Design Model
    A suite of software analysis tools for evaluating safety and operational effects of geometric design decisions on highways. The IHSDM - HSM Predictive Method 2011 Release includes six evaluation modules (Crash Prediction, Design Consistency, Intersection Review, Policy Review, Traffic Analysis, and Driver/Vehicle) and may be downloaded free-of-charge at

    The IHSDM website includes all recently published materials on IHSDM in online and/or hard copy format. Past published materials, denoted as archive, are also available; these materials are somewhat dated due to IHSDM's evolving nature, but may still contain information of interest to serious researchers. Some publications are available only for purchase from the National Technical Information Service (NTIS).

  • Traffic Control Devices
    Defines the standards used by road managers nationwide to install and maintain traffic control devices on all streets and highways.

  • Pedestrian & Bicycle Safety Tools

  • Variable Speed Limit Systems
    Speed limits that change based on road, traffic, and weather conditions.

  • Retroreflectivity
    The scientific term that describes the ability of a surface to return light back to its source. Retroreflective signs and pavement markings bounce light from vehicle headlights back toward the vehicle and the driver's eyes, making signs and pavement markings visible to the driver.

  • Law Enforcement Technology Clearinghouse
    A clearinghouse for identifying and documenting as many automation projects as possible on technology used in the collection of crash data.

  • Road Safety Audits
    The formal safety performance examination of an existing or future road or intersection by an independent, multidisciplinary team.

  • Contacts
    Office of Safety staff and primary work responsibilities.


  • USLIMITS Expert Speed Zoning Advisor

  • Resurfacing Safety Resource Allocation Program (RSRAP)
    Software developed to allow highway agencies to implement a process that selects a program of safety improvements, to be made in conjunction with resurfacing projects, that maximizes traffic safety and operational benefits resulting from the program.