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FHWA Highway Safety Programs

Chapter 3 Collecting, Analyzing, and Sharing Data

Using data to identify safety problems is fundamental to successful SHSP implementation. Just as development of the SHSP was a data-driven process, an effective implementation process also depends on appropriate use of data. These data enable managers to identify safety problems, select proper strategies and countermeasures, monitor progress toward achievement of SHSP goals and objectives, measure the effectiveness of SHSP strategies, identify needed improvements, and direct limited resources to where they have the highest potential for reducing fatalities and serious injuries.

A variety of strategies can be employed to collect data, perform analysis, and ensure SHSP stakeholders can access the data and the analysis. NHTSA Section 408 grants, established in Title 23, United States Code, through SAFETEA LU, provide funding for States to improve the timeliness, accuracy, completeness, uniformity, integration, and accessibility of safety data. In some States, multiple agencies provide funding for data collection and management through interagency agreements. Educating State legislatures on the benefits of data-driven decision-making has helped some States successfully make the case for additional safety funding.

In many States, safety data are collected by several different organizations. It is common for data collection procedures within these organizations to be well-established and difficult to change. At the same time, advances in transportation safety research highlight new data needs and improvements in hardware capability and software applications change how data is collected. To help ensure that data collection procedures respond to evolving requirements, participation of Information Technology (IT) personnel from relevant stakeholder organizations should be encouraged.

Collect Relevant Data

Given the multidisciplinary nature of SHSP efforts, types of data relevant to implementation include the following:

  • Crash Data – Type of crash (lane-departure, intersection, rear-end, etc.), weather conditions, time of day, day of week, person type (driver, occupant, pedestrian, etc.), number and severity of injuries, traffic law violations, crash location, manner of collision, number of vehicles involved, alcohol or drug impairment, direction of travel, crash diagram, narrative description of the crash.
  • Injury Surveillance – EMS response time, hospital assessment of injury severity, hospital length of stay and cost, rehabilitation time and cost.
  • Roadway – Roadway classification, roadway inventory data, traffic control devices, location referencing system, rail grade crossings, structures (bridges, tunnels), traffic volume, vehicle types on the roadway.
  • Vehicle – Vehicle Identification Number (VIN), registration information and plate, age/model/year, weight, owner information, U.S. DOT number (commercial), carrier information (commercial), inspection/out-of-service records (commercial).
  • Driver – Age and date of birth, driver history (previous convictions), license status, gender and ethnicity, education/training.
  • Law Enforcement – Citation tracking, prosecution, conviction, sentencing, case tracking, adjudication.
  • Other – Statewide occupant protection use survey, insurance data (carrier, policy number, claims cost), demographic data.

These data may be collected from a variety of sources, including State and local crash data systems and roadway inventory files, the National Fatality Analysis Reporting System (FARS), the General Estimates System (GES), the Motor Carrier Management Information System (MCMIS), the National Emergency Medical Services Information System (NEMSIS), the Crash Outcome Data Evaluation System (CODES), and others.

In many cases, important safety data are unavailable or unknown. Information in police crash reports may vary from location to location; medical records, insurance records, and licensing information may not be available or linked to the crash data; and roadway inventory information may be limited and difficult to link to the crash data system. These and other data quality problems inhibit the effectiveness of efforts to improve transportation safety. However, access to timely and accurate safety data is critical for successful SHSP implementation. The following strategies have proven successful for improving data collection, management, and analysis:

  • Include Information Technology (IT) personnel from relevant organizations on appropriate SHSP implementation teams.
  • Prepare a traffic records improvement strategic plan and link it to SHSP implementation.
  • Integrate the Traffic Records Coordinating Committee (TRCC) into the SHSP implementation team. The TRCC is responsible for identifying traffic records data system enhancement strategies to improve data access, accuracy, and timeliness.
  • Provide input to the TRCC on data collection and processing problems or on needed changes in crash report fields, roadway inventory data, traffic data, driver history data, or citation/adjudication data.
  • Establish data collection task forces or committees to promote collaboration among safety stakeholders.
  • Implement data collection technologies to reduce the number of errors and processing time for data. National Cooperative Highway Research Program (NCHRP) Synthesis 367: Technologies for Improving Safety Data provides a comprehensive summary of crash data collection innovations.
  • Provide continuous training for State and local police officers on the importance of high-quality crash data and collection techniques.
  • Provide continuous training for State and local crash report system administrators to properly handle reports with inaccurate or missing information.
  • Develop proper protocols to address crash reports that need additional investigation.
  • Develop a data standards manual that provides definitions of variables and identifies available data streams and the agencies responsible for collecting and maintaining the data.
  • Develop data submission protocols for agencies that provide data to the management system.
  • Provide training for data input personnel and analysts to understand how their efforts contribute to and are utilized by technical staff for safety program support.

Analyze the Data

Just as data were analyzed to identify emphasis areas and develop emphasis area goals, objectives, and strategies, they are analyzed to develop action plans, monitor, evaluate results, and provide feedback to update the SHSP. Analysis can involve simple statistical investigations of crash trends, types, and contributing factors. Analysis may also utilize sophisticated tools such as FHWA's Safety Analyst and the Highway Safety Manual. As a foundation for SHSP implementation, data are the basis for the following:

  • Identification of systemic safety issues as well as high-crash corridors, road segments, and intersections. By describing safety problems quantitatively, an agency knows the magnitude of the problem and can focus its efforts on areas with the greatest potential to save lives.
  • Identification of crash type. Data analysis is used to discern trends in the frequency of certain types of crashes (e.g., rear-end collisions, lane departures, impaired driving, etc.). Crash type data are used to identify SHSP emphasis areas and develop action plans.
  • Performance-based program management. Analysis of safety data allows managers to determine the extent to which the SHSP is achieving its stated goals and objectives.
  • Project selection and prioritization. Analysis of safety data helps managers select and implement appropriate systemic improvements to the transportation network and identify projects to improve safety at high-crash locations. It helps identify high-risk groups such as young, elderly, and impaired drivers as well as motorcyclists and pedestrians. Managers use these data to select and prioritize countermeasures with the greatest potential for reducing death and injury.
  • Monitoring and evaluation. Data monitoring and evaluation helps managers make course corrections as the plan advances; develop new programs using more effective countermeasures and strategies; improve existing programs; and direct resources toward implementation of the most effective programs, policies, and projects.
  • Resource justification. Data-driven prioritized road safety projects provide transportation planners, engineers, law enforcement officers, and others with justification for additional resources.

Share the Data

Local governments, MPOs, advocacy groups, and private consultants require crash data to conduct safety planning and project-related activities; therefore access to the data is critical. Some agencies managing crash and other safety-related data provide raw data as well as filtered datasets that can be readily used by local agencies. Collaboration is fostered by providing stakeholders with direct access to safety data and the training needed to analyze them. In addition data quality may be improved because data sharing often promotes local efforts to improve data accuracy.

Access to reliable data for all stakeholders enables them to more fully realize the benefits of integrating the SHSP with other transportation and safety plans (as discussed in Chapter 5). Adopting the following strategies will allow more effective and efficient data sharing practices.

  • Maintain a centralized data source accessible to all State and local agency partners ensuring everyone uses consistent information.
  • Provide training to State and local agency partners on how to gather and analyze safety data.
  • Develop policies to establish data dissemination schedules.
  • Develop a standard procedure for handling data requests that clearly identifies who will handle requests and how they will be addressed.
  • Host MPO forums to discuss data issues and enhancement strategies.
  • Employ university research centers to provide safety data analysis support to MPOs.
  • Encourage MPOs to conduct safety analysis for member jurisdictions, including crash location mapping.
  • Work with LTAPs and others to support safety planning efforts at the local level by providing data for non-State highways and developing a GIS-based integrated roadway management system.

Key Data Collection, Analysis, and Sharing Strategies:

  • Conduct initial research into a range of available data sources.
  • Collect relevant data necessary to define safety needs and support decision-making processes.
  • Prepare a traffic records improvement strategic plan and data collection task forces or committees.
  • Provide training in the collection, analysis, and use of safety data.
  • Use data to select and implement appropriate systemic improvements to the transportation network and identify projects to improve safety at high-crash locations.
  • Use data to monitor and evaluate the outcomes and results of safety projects and programs.
  • Use data to justify the need for resources to support implementation of safety projects and programs.
  • Establish data sharing protocols to ensure all stakeholders are working from the same data sets and have access to the data they need.
  • Allow State and local agency partners to query safety data directly.


Answering these questions will help stakeholders review their SHSP data collection and analysis process and identify opportunities for improvement.

  • Does your State have a traffic records improvement strategic plan?
  • Is the TRCC strategic plan integrated and/or coordinated with the SHSP?
  • Is the TRCC integrated with SHSP implementation efforts?
  • How is data collection funded? Do the agencies and organizations using the data provide funding support? Does your State make full use of all available funding (section 408, TRCC, etc.) for data collection?
  • How is data collection coordinated at the regional/local level?
  • Who provides/collects/processes/analyzes data?
  • How are data shared at the Statewide level and with whom?
  • How are data disseminated to and utilized by regional and local agencies?
  • Are data uniform and coordinated among entities?
  • Are transportation planning data utilized in SHSP implementation (i.e., travel demand models, Highway Performance Monitoring System (HPMS) data, etc.)?
  • Are GIS-based tools being utilized for analysis and visualization of roadway inventory and crash data?