Street Network Connectivity, Traffic Congestion, and Traffic Safety

Over the last two decades, street connectivity has gained substantial attention in urban planning circles as a critical environmental aspect to achieve many community goals. Despite advocacy for interconnected areas, the literature on the effects of street connectivity on transportation outcomes is still intuitive. In this study, the authors examine the effect of street connectivity on congestion levels and crash rates in neighborhoods across Utah's Wasatch Front. The authors employ propensity score matching to select pairwise neighborhood samples with similar characteristics that differ greatly in street connectivity. The authors use principal component analysis to develop a connectivity index incorporating multiple aspects of street connectivity. Congestion levels are computed as the Travel Time Index on arterials and collectors. Crash rates are calculated at three different severity levels— total, injury, and fatal. Finally, the authors use t-tests to determine whether significant differences exist between high- and low-connectivity neighborhoods. The results show that more connected neighborhoods have significantly lower congestion levels, but they do not have measurably lower (or higher) crash rates, presumably due to the prevalence of four-way intersections. This study can help guide data-driven decision-making on street connectivity standards for many of the growing urban areas across the country and globe.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Maps; References; Tables;
  • Pagination: 52p

Subject/Index Terms

Filing Info

  • Accession Number: 01760031
  • Record Type: Publication
  • Report/Paper Numbers: UT-20.19
  • Contract Numbers: 20-8076; 5H08274H
  • Created Date: Nov 24 2020 12:38PM