Analysis of Roadway Safety under Alternative Project Delivery Systems

In the United States, most highway projects have been with using the traditional design-bid-build delivery system. Moving on to regular conditions assessment, maintenance of a road is then performed on the basis of the availability of funds and the priorities established for road maintenance. When maintenance funds are scarce, serviceability of roads is impacted, which affects road safety. The alternative project delivery systems, such as design-build-operate-maintain, design-build-finance-operate-maintain, and other public-private partnership (PPP) models, provide for more consideration of the life cycle of highways. Particularly under performance-based long-term contracts, which are the norm for PPP systems, road maintenance and performance become controlling parameters in compensating contractors for their work. With serviceable, well maintained roads, it is expected that road safety records will improve. Through content analysis of PPP procurement documents and agreements, this research investigated PPP projects for their contractual safety terms, such as the design of safety payments, measurements, and safety specifications. Through statistical analysis, the research surveyed PPP projects’ roadway safety records and compared them with the safety records of states, localities/cities, and public non-PPP highways. The findings showed that safety rates for PPPs are better than those of traditionally delivered highways, but not on all dimensions. This was represented by better (lower) injury and accident/crash rates on PPP projects than those rates for state, locality, and public non-PPP projects. However, the fatality rates on PPP projects experienced instability or fluctuation, as they did not remain lower in all years and/or on all projects in comparison to public non-PPP projects (PPP fatality rates were better in comparison to those of states and localities). Additionally, this study found that PPP projects did not provide more consideration for safety beyond that normally available from traditional delivery. Safety was an objective in most (76 percent) of the projects; however, without proactive mechanisms to implement that objective. Around half of the projects mentioned safety as part of the proposal evaluation, but only two projects assigned points or weights in the evaluation. None of the projects provided ways to link the contractors’ compensation to achievement of better accident/fatality/injury rates of the projects.

  • Record URL:
  • Supplemental Notes:
    • This research was sponsored by the U.S. Department of Transportation, University Transportation Centers Program.
  • Corporate Authors:

    University of Washington, Seattle

    Seattle, WA  United States  98195

    Pacific Northwest Transportation Consortium

    University of Washington
    More Hall Room 112
    Seattle, WA  United States  98195-2700

    Office of the Assistant Secretary for Research and Technology

    University Transportation Centers Program
    Department of Transportation
    Washington, DC  United States  20590
  • Authors:
    • Aziz, Ahmed Abdel
    • Migliaccio, Giovanni C
    • Shang, Luming
  • Publication Date: 2017


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; References; Tables;
  • Pagination: 255p

Subject/Index Terms

Filing Info

  • Accession Number: 01708085
  • Record Type: Publication
  • Report/Paper Numbers: 2015-S-UW-91
  • Contract Numbers: DTRT13-G-UTC40
  • Created Date: Jun 7 2019 9:37AM