Evaluation of Safety Performance of Rural Roundabouts

Details

• Creators:
  Roy, Shibasish Dutta ; Schrock, Steven ; Kondyli, Alexandra
• Corporate Creators:
  University of Kansas. Dept. of Civil & Environmental Engineering
• Corporate Contributors:
  Kansas. Dept. of Transportation. Bureau of Research
• Subject/TRT Terms:
  Before And After Studies Benefit Cost Analysis Evaluation Fatalities Performance Roundabouts Rural Areas Safety Management Safety Performance Traffic Safety
• Publication/ Report Number:
  K-TRAN: KU-23-4
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Kansas
• Edition:
  Final Report: August 2022 – May 2024
• Corporate Publisher:
  Kansas. Dept. of Transportation. Bureau of Research
• Abstract:
  This study evaluated the safety performance of rural roundabouts in Kansas using before-and-after analysis and comparison group approaches. Study results showed that the anticipated number of injury and fatal crashes significantly decreased after the implementation of isolated rural roundabouts. The before-and-after analysis indicated a reduction of 30 injury crashes and 5 fatal crashes over the study period, and the projected number of injury crashes decreased by 45.6%, which is statistically significant at the 0.05 level. A significant decrease in fatal crashes (33.33%) and fatal and injury crashes (44.62%) was also observed. After incorporating comparison groups into the research, injury crashes decreased by 26.3 and fatal crashes decreased by 4.2, while injury crashes decreased by 46.69%, with statistical significance at an alpha level of 0.07. The total number of fatal and injury crashes also decreased significantly at the 0.06 level. The evaluation of rural interchange roundabouts revealed 18 fewer expected injury crashes throughout the duration of the study, indicating a 68.33% decrease in the projected number of injury crashes. This reduction was significant at a 0.08 level of significance. With 94% confidence, this research indicates that rural roundabouts contribute to a decrease in the numbers of fatal and injury crashes. In addition, a benefit-cost analysis of both approaches substantiated the economic value of isolated rural roundabouts, with a total benefit over 20 years of $509,487,883.63 using a straightforward before-after analysis and $429,540,426.09 using comparison groups; the calculated benefit-cost ratios were 11.16:1 and 9.41:1, respectively. Overall, the study results proved the efficacy of rural roundabouts for reducing traffic crashes and improving rural road safety in Kansas.
• Format:
  PDF
• Funding:
  C2212
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:0fa011a4727a1db37dcfde32992bfd4fd72a3d42410db4bf8b11637bda43a8983fdb4a8331c9ea1263f066c237dc50eaca9e30ec7ab8fb63c60d2aeb815a211d
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/87449/dot_87449_DS1.pdf
• File Type:
  [PDF - 2.15 MB ]