Examining the Safety Threshold for Roadway Design

This paper discusses the inherent tension between economically and feasibly designing a roadway and establishing a level of safety that society expects, in light of the movement to modify or replace standards-based design with alternative approaches. For a concrete example, the recent evolution of stopping sight distance design practice and the influence of alternative perspectives are described, along with the related attempts to propose a threshold to distinguish acceptable from unsafe design practice. Then, for perspective, the paper presents examples from private enterprise that illustrate society’s current mandates for acceptable levels of safety. By considering the costs and penalties society imposes when the level of safety provided is not high enough to avoid unacceptably harmful consequences, one can clarify what safety threshold to strive for and what amount of effort and expenditure is mandated to minimize potential harm. The paper ends with an assertion that significant improvements in crash databases are required before it is feasible to reliably assess the performance of some types of roadway design elements, along with mentioning possible changes that could improve the safety database and facilitate the introduction of alternative design frameworks. While shortcomings with crash databases is not a new issue, the move toward performance-based and other design paradigms, combined with the recent technological developments that finally make the database improvements feasible, add new urgency to rectifying the long-standing crash database problem so that safety thresholds of design decisions may be adequately evaluated.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: References; Tables;
  • Pagination: 15p
  • Monograph Title: TRB 94th Annual Meeting Compendium of Papers

Subject/Index Terms

Filing Info

  • Accession Number: 01555722
  • Record Type: Publication
  • Report/Paper Numbers: 15-4436
  • Files: TRIS, TRB, ATRI
  • Created Date: Feb 27 2015 4:43PM