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 OFFICE OF RESEARCH, DEVELOPMENT, AND TECHNOLOGY AT THE TURNER-FAIRBANK HIGHWAY RESEARCH CENTER Home
                        Research
                        Turner-Fairbank Highway Research Center
                        Research and Development
                        IHSDM


            
            In This Section
        Explore Research and Technology
                Safety Research and Development
                Interactive Highway Safety Design Model Overview
                Modules
                                Overview
                Crash Prediction Module
                Design Consistency Module
                Policy Review Module
                Traffic Analysis Module
                Driver/Vehicle Module
                Software Download
                FAQs
                Support and Training
                User Group
                User Applications and Case Studies
                Events
                Related Initiatives
                Library
                Projects
                Contacts
      
   Contact Us
      Turner-Fairbank Highway Research Center
      
                    
            United States Department of Transportation Federal Highway Administration6300 Georgetown PikeMcLean, VA 22101United States
      
          
    **Email:**TFHRC.webmaster@dot.gov
    If you are deaf, hard of hearing, or have a speech disability, please dial 7-1-1 to access telecommunications relay services.
                
                Interactive Highway Safety Design Model (IHSDM) FAQs: IHSDM Data Structure
    

    
    
    
      The basic components of the IHSDM data organization structure include users, projects, highways, intersections, interchanges, ramp terminals, roundabouts, sitesets, and evaluations. This section contains guidance for where to find information about these components and their relationships, as well as the sample IHSDM Projects provided with the software.

**Acronyms/Abbreviations**
The following acronyms/abbreviations are used in the FAQs below.

Crash Prediction Module (CPM)
	Design Consistency Module (DCM)
	Driver/Vehicle Module (DVM)
	Economic Analyses tool (EA tool)
	Federal Highway Administration (FHWA)
	Highway Safety Manual (HSM)
	Interactive Highway Safety Design Model (IHSDM)
	Policy Review Module (PRM)
	Research and Development (R&D)
	Traffic Analysis Module (TAM)

            Expand All
      Collapse All
        **Where can I find information on how projects, highways, intersections, site sets and evaluations are related?**
        For detailed information on how projects, highways, intersections, Site Sets and evaluations are related, refer to the "IHSDM Interface and Data Organization" section of the IHSDM documentation (access via Help > Help Browser from the IHSDM main menu).
  


      **Are sample projects provided with the IHSDM software?**
        The Tutorial folder of the IHSDM software contains over 20 sample archived Projects. These Projects are referenced in various Tutorial exercises, but can also be used apart from the Tutorial for users to become familiar with aspects of IHSDM Projects. Sample Projects include:

IHSDM Pike: three projects related to the 2.7 mile long IHSDM Pike are available – one with IHSDM Pike as a rural 2-lane highway (IHSDM Pike Project), one as a rural multilane highway (IHSDM Pike-Rural Multilane), and one as an urban arterial (IHSDM Pike-Urban Arterial).
	Example Project 1 – Tutorial Lesson 9: a version of IHSDM Pike used in Tutorial Lesson 9 on Output / Reporting.
	Example Freeway: An "Example Freeway" highway network that contains a 6-lane freeway segment with 2 crossroads and 2 interchanges, including C-D roads, ramps and ramp terminals.
	Example Freeway-Economic Analysis: A version of the "Example Freeway" project (see above), containing an existing highway network and two alternative cases. IHSDM Tutorial Lesson 11 (Economic Analyses Tool) uses this project as a case study.
	HSM Chapter 18 Sample Problems: 5 Projects related to HSM Chapter 18 Sample Problems (SP) 1-5 for Freeway Segments (HSM Ch 18 SP1, HSM Ch 18 SP2, HSM Ch 18 SP3, HSM Ch 18 SP4, and HSM Ch 18 SP5).
	HSM Chapter 19 Sample Problems: 6 Projects related to HSM Chapter 19 Sample Problems (SP) 1-6 for Freeway Ramps/Interchanges (HSM Ch19 SP1, HSM Ch 19 – Sample Problem 2, Entrance Ramp - HSM Ch 19 SP3, Ramp Terminals-Ch19 SP4, A4 Ramp Terminal 1-Way_Stop HSM Ch 19 SP5, and B2 Ramp Terminal AWSC_HSM Ch 19 SP6).
	Siteset-Rural Multilane: a sample Site Set, containing data for Four-Lane Undivided Segments, Four-Lane Divided Segments, Three-Legged Minor-Road Stop Control Intersections, Four-Legged Minor-Road Stop Control Intersections, and Four-Legged Signalized Intersections. This Site Set is used in Tutorial Lesson 4 (Crash Prediction Module).
	Pennsylvania I-70 Case Study: three projects related to an interchange alternatives analysis case study, including projects for the two alternatives evaluated (Alternatives 2A and 3), and a "training" version of the Alternative 2A project. These projects are used in Tutorial Lesson 4, Exercise 4.9.
	Roundabout Exercises: two projects are used in Tutorial exercises related to the roundabout crash prediction method.
	IHSDM Urban Network: three projects, which contain data for an urban arterial (major road), 4 minor roads, and their intersections (including a roundabout); used in Tutorial Lesson 4 (Crash Prediction Module), Exercises 4.12 and 4.13, and Lesson 10 (Crash Prediction Module Calibration), Exercise 10.11.
	IHSDM Freeway Example - Original Data and IHSDM Freeway Example - Reversed Data – contain data for a freeway section with two interchanges; used in Tutorial Lesson 12 (Data Considerations), Work Problem 2.
	An IHSDM Economic Analyses project (Example Freeway), related to Tutorial Lesson 11 (IHSDM Economic Analyses Tool (EA Tool) Tutorial).

    
          Last updated: Thursday, December 2, 2021 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