The Development of Local Calibration Factors – Phase II: Maryland Freeways and Ramps

The goal of the study was to develop local calibration factors (LCFs) for Maryland freeways in order to apply the predictive methods of the Highway Safety Manual (HSM) to the state. LCFs were computed for freeway segments, speed-change lanes, and signalized and stop-controlled ramp terminals (intersections of the entrance/exit ramps and the crossroads). Ramps (facilities connecting local roads to freeway travel lanes) and collector-distributor roads were excluded from the study due to insufficient historical crash data. LCFs for the studied facility types were smaller than 1.0, implying on average Maryland had fewer crashes than predicted crashes estimated by the HSM predictive method during the study period. LCFs for ramp terminals were extremely low. Due to potential under-reporting of property damage only (PDO) crashes on ramps, it is recommended that applying LCFs developed with PDO crashes should be done with caution. The report concludes with a discussion on the interpretation of LCFs and data limitations. It should be noted that Baltimore City was not part of this study.

• Record URL:
  http://www.roads.maryland.gov/OPR_Research/MD-16-SHA-MSU-4-6_LCF-II_Report.pdf
• 
• Supplemental Notes:
  • This document was sponsored by the U.S. Department of Transportation, University Transportation Centers Program.
• Corporate Authors:

  Morgan State University

  Baltimore, MD  United States  21251

  Maryland State Highway Administration

  Office of Policy and Research, 707 North Calvert Street
  Baltimore, MD  United States  21202

  Office of the Assistant Secretary for Research and Technology

  University Transportation Centers Program
  Department of Transportation
  Washington, DC  United States  20590
• Authors:
  • Shin, Hyeon-Shic
  • Lee, Young-Jae
  • Dadvar, Seyedehsan
  • Bharti, Shilpi
• Publication Date: 2016-11

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Appendices; Figures; Maps; Photos; References; Tables;
• Pagination: 239p

Subject/Index Terms

• TRT Terms: Calibration; Crash rates; Freeways; Highway safety; Interchange ramps; Speed change lanes
• Identifier Terms: Highway Safety Manual
• Geographic Terms: Maryland
• Subject Areas: Data and Information Technology; Highways; Safety and Human Factors;

Filing Info

• Accession Number: 01617687
• Record Type: Publication
• Report/Paper Numbers: MD-16-SHA-MSU-4-6
• Contract Numbers: SP409B4N
• Files: UTC, TRIS, ATRI, USDOT, STATEDOT
• Created Date: Nov 23 2016 3:54PM