Safety Evaluation of Roundabouts in Georgia

Details

• Creators:
  Guin, Angshuman ; Rodgers, Michael O. ; Gbologah, Franklin
• Corporate Creators:
  Georgia Institute of Technology. School of Civil and Environmental Engineering
• Corporate Contributors:
  Georgia Department of Transportation ; United States. Federal Highway Administration ; Georgia. Dept. of Transportation. Office of Performance-Based Management and Research
• Subject/TRT Terms:
  Highway Safety Intersections Roundabouts Roadway Safety Rural Areas Rural Highways Rural Intersections
• Publication/ Report Number:
  FHWA-GA-18-1507
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States;Georgia
• Edition:
  Final Report
• Corporate Publisher:
  Georgia. Dept. of Transporation. Office of Performance-Based Management and Research
• Abstract:
  Several previous studies have documented significant safety benefits of roundabouts in the United Sates. However, the safety benefits for a given roundabout may vary depending on factors such as the familiarity of the driving population to roundabout operation, site-specific geometric features, weather conditions, etc. To help inform GDOT’s roundabout implementation investment decisions, the current study provides a safety evaluation of 27 Georgia roundabouts. A time-dependent form of the Highway Safety Manual predictive (empirical Bayes) method was used to estimate potential crash reductions across all crashes and all injury/fatal crashes. The findings provide further evidence that roundabouts are an effective crash countermeasure. Specifically, the results show the following crash reductions: (a) A 37 to 48 percent reduction in average crash frequency for all crashes and a 51 to 60 percent reduction in average crash frequency for injury/fatal crashes at four-leg roundabouts converted from stop-controlled and conventional intersections (b) A 56 and 69 percent reduction in average crash frequency for all crashes and injury/fatal crashes, respectively, at three-leg and four-leg roundabouts converted from stop-controlled and conventional intersections The study did not consider five-leg roundabouts due to small sample size and concerns about the form of the SPF.
• Format:
  PDF
• Funding:
  0013622
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:42c11860dd2cdbc096ea0f86db32b93297482226d39c2ff1fd114c2700fc5e6e2cf095d4ea676c5af7fb66c46ff4a84360076718964a7af9b25ed67463eb600b
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/36699/dot_36699_DS1.pdf
• File Type:
  [PDF - 962.92 KB ]