Improved processes for meeting the data requirements for implementing the Highway Safety Manual (HSM) and SafetyAnalyst in Florida.

Details

• Creators:
  Alluri, Priyanka ; Saha, Dibakar ; Liu, Kaiyu ; Gan, Albert
• Corporate Creators:
  Florida International University. Lehman Center for Transportation Research
• Subject/TRT Terms:
  • Highway safety
  • Manuals
  • Implementation
  • Calibration
  • Software
  • Data collection
  • Crash data
  • Unsignalized intersections
• Publication/ Report Number:
  BDK80-977-37
• Resource Type:
  Tech Report
• Geographical Coverage:
  Florida
• Corporate Publisher:
  Florida. Department of Transportation. Research Center
• Abstract:
  Recent research in highway safety has focused on the more advanced and statistically proven techniques of highway ; safety analysis. This project focuses on the two most recent safety analysis tools, the Highway Safety Manual (HSM) ; and SafetyAnalyst. Meeting the data requirements is considered the most challenging task in implementing these ; tools. ; In the case of HSM, many of the data variables needed for deriving the HSM calibration factors are currently ; unavailable in Florida’s roadway characteristics inventory (RCI) database. This project attempts to identify and ; prioritize influential calibration variables for data collection and to determine the minimum sample sizes to estimate ; reliable calibration factors. For each facility type included in the HSM, this project applied the random forest ; technique to rank both the required and desired variables based on their importance. The variables were categorized ; into three groups: variables of primary importance; variables of secondary importance; and variables of lesser ; importance. The minimum sample sizes to estimate reliable calibration factors for different facility types were also ; determined. It was found that the minimum sample size of 30-50 sites with at least 100 crashes per year, as ; recommended by HSM, is insufficient to achieve the desired accuracy for nearly all facility types. ; Compared to HSM, SafetyAnalyst has lesser but different data requirements. Two major efforts in applying ; SafetyAnalyst involve the conversion of local data into the strict data format required by SafetyAnalyst and the ; development of jurisdiction-specific safety performance functions (SPFs). This project developed a software ; program to convert the crash and roadway data for Florida’s state roads to “import” files used by SafetyAnalyst. In ; addition, this project also developed the SPFs for unsignalized intersections to supplement those of other facilities ; which were developed under a separate project. For demonstration, SafetyAnalyst was applied using Florida’s data to ; identify high crash locations. Recommendations for deploying SafetyAnalyst are also provided.
  More +
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/27226/dot_27226_DS1.pdf
• File Type:
  [PDF - 1.76 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:ee52533d58651320f8a353e348a991da2b0c93f410215ddf577d0f74b86a95c023c86a67f72a07a8b48b36685fb9f0a7074285b4f20051194446392c82f434d4