Evaluating Effectiveness of Crash Type SPFs in Safety Management: Comparing the Effectiveness of Network Screening and Diagnostic Methods Using Aggregate SPFs and Test of Proportion With Crash Type SPFs

Details

• Creators:
  Kononov, Jake ; Williams, Jim ; Thomas, Scott
• Corporate Creators:
  Apex Design, PC ; DiExSys, LLC
• Corporate Contributors:
  Colorado. Department of Transportation. Applied Research & Innovations Branch ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  Bayes' Theorem Crash Types Empirical Methods Evaluation Fatalities Measures Of Effectiveness Pattern Recognition Systems Predictive Models
• Publication/ Report Number:
  CDOT-2020-12
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Colorado
• Edition:
  Final Report
• Corporate Publisher:
  Colorado. Dept. of Transportation. Applied Research and Innovation Branch
• Abstract:
  The intent of this project is to compare the effectiveness of network screening and diagnostic methods using aggregate SPFs and Test of Proportions with crash type SPFs. Both methods were applied to the same datasets containing crash history and exposure data. Sixteen (16) frequency and severity Colorado-specific crash type SPFs were developed for the following facilities: Rural 2 lane highways, Urban 4-Lane Divided Freeways, Urban 4-Lane, Urban 3-Leg, Divided, Unsignalized Intersections and Urban 4-Lane, 4-Leg, Divided, Signalized Intersections. These new models were used to evaluate and compare the effectiveness of both methods for diagnostics and network screening. Implementation: CDOT will consider incorporating the following findings in its safety management practices: 1) In some cases when two or more major crash types are concurrently elevated the overall number of crashes may be elevated without upsetting the balance of proportions among crash types. Such events happen infrequently but can’t be detected by a test of proportions. 2) Test of proportion presently does not have a capability to detect elevated crash severity of a specific crash type. An effective strategy to remedy the situation is to develop stratified diagnostic norms for injury and fatal crashes only and to introduce injury focused level of diagnostic tests in addition to presently used tests for crashes of all severity.
• Format:
  PDF
• Funding:
  319.02
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:d2b40da6338bb7d9fb183116e46f33060dfef78398eb5f6a89cf25ef30123df84cd4db9989f762097083d53e94194ac0c459ea333673cdc5054c2316cc404f47
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/88627/dot_88627_DS1.pdf
• File Type:
  [PDF - 6.82 MB ]