FEDERAL HIGHWAY ADMINISTRATION

Data

and

Safety

Analysis

Tools
The Federal Highway Administration 

(FHWA) provides and supports a wide 

range of data and safety analysis tools 

for State and local practitioners. These 

tools have been designed to assist 

practitioners understand safety problems 

on their roadways, link crashes to their 

roadway environments, and select and 

apply appropriate countermeasures. 

The tools’ capabilities range from simple 

to complex. Some provide general 

information; others allow more complex 

analysis of crashes under specific 

conditions and/or with specific roadway 

features. This brochure provides an 

overview of these tools and information 

on how to access them.

FHWA Data and Safety 

Analysis Tools
Model Minimum Inventory of Roadway 

Elements – MMIRE

Safety data are key elements to sound decisions on the design 

and operation of roadways. Critical safety data include not only 

crash information, but also roadway inventory, traffic, driver 

history, and citation/adjudication data. MMIRE includes a listing 

of roadway inventory and traffic elements essential to safety 

management and proposes standardized coding for each.

http://www.mmire.org

Digital Highway Measurement System – 

DHM

The product of 6 years of research and development by FHWA, 

DHM is a high-accuracy roadway and roadside data collection 

vehicle. The DHM vehicle is instrumented with multiple 

technologies, sensors, and computer analysis capabilities to 

collect and process raw highway data and produce readily 

useable, electronic data files. Using information collected on, 

over, and under the road, DHM enables the user to generate asbuilt plans, take roadside inventories, and measure pavement 

surface and subsurface conditions.

The website is currently under development. For more 

information, contact Lincoln Cobb, lincoln.cobb@dot.gov.

Highway Safety Information System – HSIS

HSIS is a multi-state database that contains crash, roadway 

inventory, and traffic volume data for a select group of States. 

The participating States were selected based on the quality of 

data available and their ability to merge data from the various 

files. The HSIS is used to analyze a large number of safety 

problems, ranging from the more basic “problem identification” 

issues to modeling efforts that attempt to predict future 

accidents from roadway characteristics and traffic factors. The 

HSIS is used in support of the FHWA safety research program 

and as input to program and policy decisions. The HSIS is also 

available to analysts conducting research under the National 

Cooperative Highway Research Program, university researchers, 

and others involved in the study of highway safety.

http://www.hsisinfo.org

Data Collection and 

Management Tools

FHWA Data and Safety Analysis Tools | 3
Highway Safety Manual – HSM

The HSM provides information and tools to assist transportation 

professionals in making decisions that have a positive impact on 

highway safety. Focusing on objective measures of safety with a 

primary emphasis on crash frequency and severity, the HSM includes 

analytical tools to quantify and predict the safety performance of the 

variety of elements considered in road planning, design, maintenance, 

construction, and operation. The HSM also includes a synthesis of 

validated highway research and procedures that are adapted and 

integrated into practice. 

http://www.highwaysafetymanual.org

Interactive Highway Safety Design Model – 

IHSDM

IHSDM is a suite of software analysis tools for evaluating the safety and 

operational effects of geometric design decisions. The current version 

checks existing or proposed two-lane rural highway designs against 

relevant design policy values and provides estimates of a design’s 

expected safety and operational performance. Future expansion of 

IHSDM crash prediction capabilities to include rural multilane highways 

and urban/suburban arterials is planned, to match the 1st Edition 

Highway Safety Manual. Intended users include highway project 

managers, designers, and traffic and safety reviewers in State and local 

highway agencies and engineering consulting firms. IHSDM currently 

includes five evaluation modules – crash prediction, design consistency, 

intersection review, policy review, and traffic analysis. A beta version of 

a sixth module – driver/vehicle – will be included in the 2008 release.

http://www.tfhrc.gov/safety/ihsdm/ihsdm.htm

http://www.ihsdm.org (to download IHSDM software and for 

access to the new IHSDM Wiki)

FHWA GIS Safety Analysis Tools v.4.0

Computerized crash analysis systems in which crash data, roadway 

inventory data, and traffic operations data can be merged are used in 

many state and municipalities to identify problem locations and assess 

the effectiveness of implemented countermeasures. By integrating this 

traditional system with a geographical information system (GIS), which 

offers spatial referencing capabilities and graphical displays, a more 

effective crash analysis program can be realized. The analysis tools 

include five separate programs to evaluate crashes: Spot/Intersection 

Analysis, Strip Analysis, Cluster Analysis, Sliding-Scale Analysis, and 

Corridor Analysis.

http://www.hsisinfo.org/hsis.cfm?num=8&page=1

Safety Analyst

SafetyAnalyst assists State and local highway agencies to program 

site-specific highway safety improvements for implementation. It 

incorporates state-of-the-art safety management approaches in 

computerized analytical tools for guiding the decision-making process 

to identify safety improvement needs and develop a system wide 

program of site-specific improvement projects. With a strong basis 

in cost-effectiveness analysis, SafetyAnalyst can play an important 

role in ensuring that highway agencies receive the greatest possible 

benefit from each dollar spent on safety.

http://www.safetyanalyst.org

Safety Data 

Analysis Tools
Pedestrian and Bicycle Crash Analysis Tool 

– PBCAT

PBCAT is a software application designed to assist State 

and local pedestrian and bicycle coordinators, planners, and 

engineers address pedestrian and bicyclist crash problems. 

PBCAT helps users create a database of details associated with 

crashes between motor vehicles and pedestrians or bicyclists, 

analyze the data, produce reports, and select countermeasures 

to address problems identified.

http://www.walkinginfo.org/facts/pbcat/index.cfm

Pedestrian Safety Guide and 

Countermeasure Selection System – 

PEDSAFE

PEDSAFE provides practitioners with the latest information 

available for improving the safety and mobility of those who 

walk. This online tool gives users a list of possible engineering, 

education, and/or enforcement treatments to improve 

pedestrian safety and/or mobility based on user input about a 

specific location. 

http://www.walkinginfo.org/pedsafe/index.cfm

Bicycle Countermeasure Selection System 

– BIKESAFE

BIKESAFE provides practitioners with the latest information 

available for improving the safety and mobility of those who 

bicycle. BIKESAFE’s resources include an overview of bicycling 

in today’s transportation system and information about bicycle 

crash factors and analysis and selecting and implementing 

bicycling improvements. BIKESAFE’s tools allow users to select 

appropriate countermeasures or treatments to address specific 

bicycling objectives or crash problems.

http://www.bicyclinginfo.org/bikesafe

Pedestrian and Bicycle Geographic 

Information System (GIS) Safety Tools

GIS software turns statistical data (such as accidents) and 

geographic data (such as roads and crash locations) into 

meaningful information for spatial analysis and mapping. In 

this suite of tools, GIS-based analytical techniques have been 

applied to a series of pedestrian and bicycle safety issues, 

including safe routes for walking to school, selection of streets 

for bicycle routes, and high pedestrian crash zones. Users 

downloading these tools must meet minimum GIS software 

requirements.

http://www.hsisinfo.org/hsis.cfm?num=9&page=1

Pedestrian and 

Bicycle Safety Tools

FHWA Data and Safety Analysis Tools | 5
Interchange Safety Analysis Tool – ISAT

ISAT provides design and safety engineers with an automated tool 

for assessing the safety effects of basic geometric design at typical 

existing interchange and adjacent roadway network. ISAT can also 

be used to predict the safety performance of design alternatives 

for new interchanges and prior to reconstruction of existing 

interchanges. The primary outputs from an analysis include: the 

number of predicted crashes for the entire interchange area, the 

number of predicted crashes by interchange element type, the 

number of predicted crashes by year, and the number of predicted 

crashes by collision type. 

The ISAT user manual is available from http://www.tfhrc.gov/

safety/pubs/07045/index.htm. The ISAT tool is available in 

Excel spreadsheet format. For more information contact Wei Zhang, 

wei.zhang@dot.gov, or Joe Bared, joe.bared@dot.gov.

Surrogate Safety Assessment Module – 

SSAM

SSAM is a tool for traffic engineers to perform comparative safety 

analysis of highway design alternatives using traffic simulation 

models. The software combines traffic microsimulation and 

automated conflict analysis. It is designed to be compatible with 

as many traffic simulation models as possible, such as VISSIM, 

Paramics, AIMSUN, and TEXAS. SSAM uses the best possible 

surrogate measures (i.e., most representative of crash propensity) 

that are observable in simulation models. It also supports flexible 

analysis (e.g., different aggregations of statistics, different 

visualization types).

http://www.tfhrc.gov/safety/pubs/08049/index.htm

(Techbrief)

Additional SSAM documentation is available in two FHWA reports, 

which can be found at http://www.tfhrc.gov/safety/

intersect.htm.

· Surrogate Safety Assessment Model and Validation: Final Report, 

FHWA-HRT-08-051.

· Surrogate Safety Assessment Model (SSAM): Software User 

Manual, FHWA-HRT-08-050. 

The SSAM software and open source code is available from 

Siemens Energy and Automation at http://www.itssiemens.com/

research/ssam. 

Intersection/

Interchange Safety 

Analysis Tools
Finite Element Analysis – FEA

FEA is an efficient and cost-effective tool to assist in the design 

of safer highway guardrails, bridge supports, sign-posts, and 

other roadside structures. Roadside safety feature FEA involves 

analyzing the computer-simulated impact of two bodies – a 

model of a specific motor vehicle colliding into a model of a 

specific roadside safety structure. Using FEA, researchers and 

engineers can study the complex interactions associated with 

crashes in ways which are not possible using actual crash tests.

http://www.tfhrc.gov/safety/crash/index.htm

Vehicle Dynamics Analysis – VDA

VDA, another type of digital simulation, is much less demanding 

of computer resources than FEA. VDA looks only at the effects of 

uneven terrain on the trajectory of a vehicle driving over it. For a 

particular median profile and barrier location, VDA can indicate 

whether a particular vehicle at a give speed and impact angle is 

likely to go over the barrier, to underride the barrier, or properly 

engage the barrier. For more information, contact Ken Opiela, 

kenneth.opiela@dot.gov.

Crash Simulation 

and Vehicle 

Dynamics Tools

FHWA Data and Safety Analysis Tools | 7
Robert Pollack

robert.pollack@dot.gov

202-366-5019

Lincoln Cobb

lincoln.cobb@dot.gov

202-493-3313 

Carol Tan

carol.tan@dot.gov

202-493-3315

For more information 

about data and safety 

analysis tools, contact:

FHWA-SA-09-002