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South Dakota Department of Transportation
Project Synopsis

Title: Factors Contributing to South Dakota Crash & Fatality Rates
Project Researcher: Maria Drake, Purdue University/CATS
Project Manager: Christina Bennett
Research Period: 3/4/2004 - 11/30/2005
Cost: $65,866.00

Problem Statement:Traffic crash and fatality rates reported in South Dakota appear to be higher than those reported by surrounding states. However, unique circumstances in each state may affect crash and fatality reporting and lessen the significance of direct comparisons. The way the crash data itself is collected and categorized may vary on a state-by-state basis. Regardless of the questions surrounding comparative statistics, the State of South Dakota is clearly aware that its crash and fatality rates have fluctuated over time. During the energy crisis of the 1970s when speed limits were lowered, crash rates appear to have decreased relative to prior years, when speed limits were higher. Conversely, when the legal drinking age was lower than it is now and enforcement of alcohol-related driving offenses was not as focused, crashes and fatalities in certain categories reflected appreciably higher rates.

A wide range of common factors contributes to traffic safety in all states. The treatments used to reduce crash and fatality rates can often vary greatly by each state, however. Prevailing attitudes related to traffic safety in South Dakota have recently drawn specific interest, particularly when crash and fatality statistics are compared to other states. Recent traffic safety concerns have led to several questions about how similar states are attempting to lower crashes when compared to South Dakotas efforts, including:

  • Would stronger educational programs promoting traffic safety and awareness help lower crash rates?

  • Are safety programs effectively promoted and instilled around the state?

  • Do prevailing laws governing speed limits, driving ages, alcohol use, seatbelt use, other vehicle safety features, etc, appropriately promote traffic safety?

  • Are law enforcement personnel and resources at sufficient levels for the traffic safety needs of the general public?

  • Do crash rates among demographic groups vary enough to suggest reallocation of traffic safety resources to groups exhibiting higher risk levels?

  • Does the geography of the state contribute to higher crash fatality rates (e.g., long distances between medical facilities)?

  • Do the composition of drivers manuals and drivers tests promote safe driving habits among the public?

  • Do certain roadway conditions in the state contribute to higher crash rates?

  • Do roads under local government jurisdiction have a different set of matters concerning traffic safety?

  • South Dakota needs to formulate actions that could potentially reduce crash and fatality rates within the state. These actions should be based upon a careful review of the crash and fatality rates in South Dakota over the past several years, followed by a thorough investigation of primary contributory factors. The entire process would require comparison with other states to determine where South Dakota stands relative to promoting a safe driving environment. Once the factors that contribute to higher crash rates are identified, the state will have the means to better allocate resources to promote better traffic safety.

    Findings: The lack of necessary information presented the project with substantial limitations in terms of analyzing South Dakota's crash and fatality rates. In response, the Center for the Advancement of Transportation Safety (CATS) produced a statistical model to estimate the degree of underreporting in counties with high Native American populations and provide the SDDOT with justification to engage in further investigations of crash reporting methods. The model also provided rough estimates of how many crashes could potentially be missing. Finally, the research team determined that the best course of action for the desired comparative analyses was to proceed using the FARS database only, where at least some information could be gleaned from the data available. Based upon the limited analyses that could be conducted, the researchers determined that the primary focus areas for the state consist of the following six areas: Underreporting, Rollover Crashes, Restraint Use, Alcohol, Speeding, and Young Drivers.

    Research Objectives:
    1  Identify critical factors involving driver behavior, traffic safety education, traffic law governance, and roadway characteristics that could contribute to higher crash and fatality rates in South Dakota compared to similar states.
    2  Develop performance measures that can be used to compare South Dakota's crash and fatality rates to similar states, and also used to gauge the effectiveness of South Dakota's progressive efforts to improve roadway safety.
    3  Formulate a plan that responds to the critical factors and defined performance measures, along with recommendations for a prioritized set of alternatives that includes estimates of costs and benefits for each alternative, aimed at reducing crash and

    Research Tasks:
    1  Meet with the project's Technical Panel to review the project scope and work plan.
    2  Review all material furnished by the project's Technical Panel related to South Dakota traffic crashes and fatalities, with an emphasis on identifying factors that can be correlated to high crash and fatality rates.
    3  Review crash and fatality statistics from a minimum of 6 comparable states with an emphasis on identifying factors that may contribute to crash and fatality rates significantly different from South Dakota's.
    4  Compare the crash and fatality reporting practices of South Dakota to the other states reviewed (particularly within FARS reporting), note any discrepancies, and determine the ultimate significance of those discrepancies on the reported crash and fat
    5  Analyze the factors identified in the previous tasks and propose, for review and approval of the Technical Panel, corresponding performance measures that can be used for benchmark comparison with the comparable states, and also used to track South Da
    6  Upon approval of the Technical Panel, compare South Dakota's measures to those from other states, and also identify and prioritize those factors that significantly affect reported crash and fatality rates.
    7  Based on feedback and approval of the prioritized listing by the Technical Panel, develop a plan that recommends focus areas with anticipated resource allocations and allocation estimates, and also includes implementation costs, benefits, and ongoing
    8  Upon review and approval of the plan to reduce crash and fatality rates in South Dakota, prepare a final report and executive summary of the research methodology, findings, conclusions, and recommendations.
    9  Make an executive presentation to the SDDOT Research Review Board at the conclusion of the project.

    Documents Available:
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