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1 1. Introduction 1.1 Research Problem Statement: The research problem statement, as outlined in the Statement of Work for the project, is quoted below: There is a critical need to obtain accurate and reliable "real-world" crash data to improve vehicle and highway safety. The use of Event Data Recorder (EDR) information has the ability to profoundly affect roadside safety. EDRs are capable of capturing vehicle dynamics data, such as vehicle speed; lateral and longitudinal acceleration-time histories; principal direction of force on the vehicle; the status of braking, steering, seat belt usage, and air bag deployment; and other valuable crash information. This represents a new source of objective data for the highway and vehicle safety community because it will provide a "real world" connection between controlled test results and actual field performance of vehicles and highway design features. EDRs have the potential to capture a large number of crash-related and other data elements for a wide range of users with different data needs. The data elements related to improving vehicle safety and driver performance are being used, but little has been done to apply the data elements to roadside safety analysis. Research can identify data elements relevant to roadside safety and improve methods to retrieve, store, and access these data. 1.2 Objectives and Scope The objectives of this research program were to (1) recommend a minimum set of EDR data elements for roadside safety analysis and (2) recommend procedures for the retrieval, storage, and use of EDR data from vehicle crashes to include legal and public acceptability of EDR use. To accomplish these objectives, the study was delineated into the following seven (7) tasks: 1. Conduct literature review and meet with an EDR data collection agency 2. Identify existing and potential EDR data elements that could be used to improve vehicle and roadside safety. 3. Identify and prioritize EDR Data needs.
2 4. Investigate current methods for initial retrieval and storage methods for EDR data. 5. Prepare an interim report documenting the findings of Tasks 2 through 4. 6. Recommend procedures for improved retrieval, storage, and use of EDR crash data to include legal and public acceptability of EDR use. 7. Submit a final report that documents the entire research effort. 1.3 Research Approach This section describes the technical approach for conducting National Cooperative Highway Research Program (NCHRP) Project 17-24 âUse of Event Data Recorder (EDR) Technology for Roadside Crash Data Analysisâ. 1.3.1 Survey of EDR Literature and Current Practices This objective of this task was to determine current U.S. and international methods and practices for the collection, retrieval, archival, and analysis of EDR data for roadside and vehicle safety. The research team performed a comprehensive literature survey of existing literature on the use of EDR data for roadside and vehicle safety. The review included examination of existing studies performed by the National Highway Traffic Safety (NHTSA) Event Data Recorder Working Group, the NHTSA Truck and Bus EDR Working Group, and the National Transportation Safety Board (NTSB) Symposia on Data Recorders in Transportation. The research team next met several times with NHTSA to discuss their growing EDR data collection efforts. NHTSA collects EDR data as part of their in-depth accident investigation research. Topics of discussion included (1) NHTSA EDR data collection, (2) current EDR data storage methods, and (3) methodologies for linking with NHTSA highway accident databases, e.g., National Automotive Sampling System Crashworthiness Data System (NASS / CDS). The research team continued these discussions with NHTSA throughout the term of the project in order to follow the development of the NHTSA EDR data collection practices. The research team summarized the results of the literature and the initial NHTSA meeting in a white paper on current EDR practices. 1.3.2 Determine Existing and Potential Future EDR Data Elements The objective of this task was to determine existing and potential future EDR data elements. The resulting list of EDR data elements formed a catalog of data element sources from which a minimum set of roadside safety-related data elements could be selected. The team investigated those safety-related data elements that could be provided
3 by EDRs â both by current and potential future devices. This investigation was based upon (a) production EDR systems installed by automakers, (b) aftermarket EDR systems which could be retrofit to a car, (c) availability of data in other electronic control units, e.g. anti-lock braking units, (d) data elements stored in Automated Crash Notification systems, (e) availability of current sensors, (f) data elements proposed in the NHTSA proposed rule on EDRs, and (g) data elements proposed by EDR standards groups. As much of the data on existing EDRs is proprietary, this was a particularly challenging task to accomplish. Key to the success of this task was the establishment of an Expert Advisory Group of subject experts who could provide insight into safety data needs, existing EDR design practices, and emerging technological directions for EDRs. Of particular importance was the broad representation from the automakers whose systems are the source of all existing and potential EDR data. Our Expert Advisory Group included EDR subject experts from GM, Ford, Daimler-Chrysler, Honda, Nissan, Mitsubishi, and Volkswagen. Many of the findings of this project were obtained through interviews with these industry experts who volunteered their insights into current and future EDR practices. A second crucial source of information was the research team participation with the professional societies and industry groups which are developing standards or position papers for EDRs. The Principal Investigator joined the Institute of Electrical and Electronics Engineers (IEEE) P1616 Standards Working Group, which has now developed a standard for Motor Vehicle Event Data Recorders (MVEDRs), and the Society of Automotive Engineers (SAE) J1698 Standards group, which has now developed a recommended practice for EDR output formats for cars and light-duty trucks. The research team has also followed the progress of other standards and industry groups, including the International Organization for Standardization (ISO) and the Technology and Maintenance Council of the American Trucking Associations, who are developing EDR related standards and position papers. 1.3.3 Identify and Prioritize EDR Data Needs This task developed a catalog of EDR data needs which support vehicle and roadside safety research and design. The approach was to match the data needs of the vehicle and roadside safety community with available or potential EDR data elements. From this analysis, this task developed a recommended minimum EDR data set to support highway crash data analysis. The research team pursued several avenues to methodically identify additional data elements that could be captured using EDR technology. Candidate data elements fell into two categories: (1) data elements, currently being collected manually, which could be collected by EDRs, and (2) data elements which were not collected previously because the data collection capabilities of EDRs were not previously available. The catalog was developed by:
4 ⢠Analysis of Existing Accident Databases. One important use of EDR data will be replace or improve data collection for the accident databases. The research team methodically examined existing eleven crash databases and recommended database formats for candidate EDR data element needs. The databases included U.S. national accident databases, state accident databases, specialized roadside safety databases, and specialized commercial truck accident databases. The research team also examined recommended databases formats or extensions including the Minimum Model Uniform Crash Criteria (MMUCC), NCHRP 350 data requirements, and NCHRP 22-15 recommended data extensions to NASS/CDS. ⢠Literature Review of Roadside Safety Data Needs. The research team conducted an extensive review of the roadside technical literature to identify recommended improvements to data elements presently collected, and to identify data elements not presently captured that could be of significant value to the roadside safety community. ⢠Develop a Catalog of Potential EDR Data Elements. Not all data elements needed for roadside safety analysis can be captured in an EDR. Fundamentally, an EDR is a vehicle-mounted device and can record only what can be measured from the vehicle. However, the performance of roadside features can sometimes be inferred from the performance of the vehicle. After analysis of the data elements in each database and the technical literature, a comparison was made with the listing of current and potential EDR capabilities to ascertain potential data elements. The extraction process resulted in a catalog of elements representing the intersection of feasible EDR data elements and matching data element needs. The data elements from each of these data sources were merged into a data catalog of recommended EDR Data Elements for highway crash data analysis. ⢠Prioritize Candidate Data Elements that could be collected from EDRs. Because there may be insufficient memory in an EDR to store all data elements of interest, the candidate data elements were prioritized by their importance to roadside safety analyses. This program prioritized the candidate data elements through consultation with subject experts in roadside safety from the state transportation agencies, federal agencies, research universities, automakers, and other organizations. Of particular importance was a priority ranking exercise conducted in collaboration with the American Association of State Highway and Transportation Officials (AASHTO) Technical Committee on Roadside Safety. The results of this task were documented in a white paper which was presented to the Project Panel for review. 1.3.4 Current Methods for Retrieval, Storage, and Subsequent Use of EDR Data This objective of task was to discuss current methods for initial retrieval and storage of, as well as subsequent use of, EDR crash data for roadside safety analysis. There are currently no standards for retrieval or long-term storage of EDR data. Through interviews with the automakers, NHTSA, field accident investigators, and retrieval equipment manufacturers, the research team investigated current EDR data retrieval
5 methods and issues, the lack of automated methods for exporting EDR data to accident databases, and the need for standardized methods of long-term EDR data storage. 1.3.5 Interim Report This task prepared an interim report which summarized the project findings on candidate EDR data elements and recommended methods for retrieving / storing EDR data. 1.3.6 Recommendations for Improved Retrieval, Storage, and Use of EDR Data Based upon the findings of earlier tasks, this task produced a statement of recommended practices for the retrieval, storage, and use of EDR crash data. The recommendations consider resource requirements, and cost-effectiveness. This task identified possible obstacles to implementing the recommended procedures. The task conducted two special studies on the legal and public acceptability of EDR use. 1.3.7 Final Report This task documented the findings and recommendations of the research project. The report was focused to encourage the vehicle manufacturers and highway safety research agencies to begin implementation of the project conclusions.
