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FHWA Home / Safety / SHSP / Strategic Highway Safety Plans: A Champion's Guidebook to Saving Lives, Second Edition

Strategic Highway Safety Plans: A Champion's Guidebook to Saving Lives, Second Edition

Chapter 2 – Data Collection and Analysis

Introduction

The SHSP is a data-driven process. All elements of the SHSP process, from development to evaluation, require States to analyze and make effective use of State, regional, local and tribal safety data.

Data enable managers to identify safety problems, select proper strategies and countermeasures, monitor progress toward achieving SHSP goals and objectives, measure the effectiveness of SHSP strategies, identify needed improvements, and direct limited resources to the highest potential for reducing fatalities and serious injuries. A variety of strategies can be employed to improve and collect data, perform analysis, and allow SHSP stakeholders access to the data and analysis. For example, States may qualify for a State Traffic Safety Information System Grant (NHTSA Section 405) for data improvement activities, such as improving the timeliness, accuracy, completeness, uniformity, integration, and accessibility of data that is needed to identify priorities for Federal, State, and local highway and traffic safety programs. In some States, multiple agencies provide funding for data collection and management through interagency agreements.

States should strive to improve the safety data needed to identify priorities for Federal, State, regional, tribal and local highway and traffic safety programs. When developing their SHSP, they should use the best available data to identify SHSP initiatives and plan data improvements, if needed.

To advance data gathering capabilities, States should develop an active partnership with the TRCC. TRCCs are responsible for identifying data system enhancement strategies that can affect access to data, as well as its accuracy and timeliness. FHWA and NHTSA data improvement programs, such as the Crash and Roadway Data Improvement Program (CDIP), the Roadway Data Improvement Program (RDIP), and NHTSA’s Traffic Records Assessments, also provide opportunities to improve data systems. They are designed to assess the strengths and weaknesses of State safety data systems and offer expert consultation and recommendations for corrections and other improvements.

Availability of complete and accurate crash data for all public roads is a critical highway safety issue. Some States identify the need to upgrade, improve, and standardize the traffic records information system as an emphasis area in the SHSP to improve the completeness and accuracy of the safety data. This makes safety data improvements a priority, which will lead to a better SHSP in the future.

Types of Data

A variety of data are available to support the development of SHSPs. These include the following:

The data may be collected from various 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), Federal Railroad Administration Highway-Rail Crossing Inventory Data, and others.

Data Integration

Data integration refers to connecting to, combining, and/or linking data residing in various systems to provide a unified view of the data. With respect to highway safety, data integration can help SHSP leaders better understand highway safety needs and develop effective strategies for addressing them. Currently, each State maintains a crash database to which local agencies are required to submit crash reports. However, crash data alone do not typically provide sufficient information on the characteristics of the roadway, vehicle, driver experience, or medical consequences. When crash data are linked to (or integrated with) roadway inventory, driver licensing, vehicle registration, citation, conviction, EMS, death certificate, census, and other data, it is possible to evaluate the relationship among the roadway, vehicle, and human factors at the time of the crash. Linkage to medical information clarifies level of injury and other crash outcomes. For example, plotting lane departure crashes by location can provide valuable information about where these crashes have occurred in the past. Combining lane departure crash location data with roadway inventory data (shoulder widths, rumble strips/stripes, cable median barriers, curve configurations, hills, etc.) provides greater understanding of the relationship between roadway configuration and lane departure crashes and enables SHSP leaders to develop effective strategies to reduce them. The integration of these two datasets (crash data and roadway inventory) provides more and better information than either of them provide individually. In addition, integrating databases promotes collaboration among the agencies, which can lead to data collection improvements.

Data Collection and Management

Safety data are fundamental to SHSP development. 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. Of all the data types needed to develop and evaluate an SHSP, perhaps the most frequently used are crash data. But other safety data (e.g., vehicle, roadway, behavioral) also can and should be used to effectively inform SHSP decisions.

Safety data collection is a complex process that requires collaboration among agencies, organizations, modes of transportation, and disciplines. One method for establishing collaboration is accomplished through the State TRCC, which facilitates project planning, coordination, and implementation designed to improve a State’s traffic records system and oversees the State Traffic Records Strategic Plan, which details the critical traffic records data issues. Typically, all levels of law enforcement are represented on the TRCC. Some States develop a data emphasis area team to work in collaboration with the TRCC to improve crash data collection, distribution, and management processes and to determine what data to analyze as well as appropriate analysis methods. This may help all involved organizations to not only understand the need for data improvements, but also to agree on the priority areas identified through data analysis.

Data Analysis

States must analyze the available safety data to identify the critical highway safety issues and safety improvement opportunities (23 U.S.C. 148(a)(12)(B)). The analysis is used to develop emphasis area goals, objectives, and strategies and action plans; monitor and evaluate results; and provide feedback for future updates to the SHSP.

Analysis can involve simple statistical investigations of crash trends, types, and contributing factors, or use advanced methods such as those presented in the Highway Safety Manual (HSM). The basic data analysis required to support the SHSP process is usually performed in-house. If States feel like they need additional data analysis assistance, this can often be provided by university research centers, other State agencies that work with similar data, etc. Data are used as a foundation for identifying SHSP priorities for the SHSP process and serve as the basis for the following:

Data Sharing

Local governments, MPOs, advocacy groups, and others require safety data for conducting safety planning and project-related activities. Some State agencies provide raw data, as well as filtered datasets that can be readily used by local agencies. Collaboration is fostered by providing stakeholders with access to safety data and training on analysis techniques. Data sharing also promotes local efforts to improve data accuracy.

Stakeholder access to reliable data helps provide consistency between the SHSP and other transportation and safety plans. Some effective and efficient data sharing practices include:

Checklist

Following the recommended steps in the checklist below will help support the data collection, management, analysis, and sharing procedures necessary for developing an SHSP.

❑ Develop a data emphasis area team to collaborate with the State TRCC to improve crash data collection, distribution, and management processes and to determine what data to analyze as well as appropriate analysis methods.

❑ Analyze the available data to identify critical highway safety issues, safety improvement opportunities, and emphasis areas.

❑ Provide a mechanism for State and local agency partners to access consistent data (such as a data fact book or a web-based centralized data site).

❑ Conduct forums to discuss safety data issues and enhancement strategies.

❑ Provide safety data and analysis to internal and/or external partners to support safety efforts.

❑ Encourage MPOs to conduct safety analysis for their member jurisdictions.

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Page last modified on March 25, 2013
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