Application of Interactive Highway Safety Design Model for Safety Evaluation of Foreign Road Designs: Case of Portuguese Rural Highway

Stepping away from the traditional design-speed concept as unique tool in road design safety monitoring, some countries evolved to the use of advanced design consistency procedures based on speed-profile estimates and expected crash frequency models. However, these procedures were based on long-term research, and have reached a level of development that is hardly replicable in the short-term by every country. Countries bereft of these tools tend to use foreign procedures with its related applicability issues. Benchmarking such methods in countries where alternative methods are available is therefore a major concern. The Interactive Highway Safety Design Model (IHSDM) is such an advanced tool. Four of its six evaluation modules are potentially relevant for direct use outside the US: the Crash Prediction Module (CPM), the Design Consistency Module (DCM), the Traffic Analysis Module and the Driver-Vehicle Module. Three of these relevant IHSDM modules were used in the analysis of a dangerous stretch of a Portuguese single carriageway two-lane rural highway and compared to local advanced procedures and observed data. The PERVEL – Dangerous Curves Detection System, a procedure for the detection of inconsistent horizontal curves in Portuguese single carriageway rural roads, was used in the evaluation of IHSDM speed estimates and DCM results. Additionally, the calibration of the CPM to the Portuguese context is described. Results show that the detected inconsistent curves by both methods are associated with higher accident frequencies than the remaining elements. The application of IHSDM demonstrated its effectiveness in the detection of dangerous road curves, overestimating however the expected accident frequencies.


  • English

Media Info

  • Media Type: DVD
  • Features: Figures; Photos; References; Tables;
  • Pagination: 15p
  • Monograph Title: TRB 90th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

Filing Info

  • Accession Number: 01333484
  • Record Type: Publication
  • Report/Paper Numbers: 11-3050
  • Files: TRIS, TRB
  • Created Date: Mar 21 2011 2:14PM