Rural variable speed limits : phase II.

Details

• Creators:
  Young, Rhonda ; Sabawat, Vijay ; Saha, Promothes ; Sui, Yanfei
• Corporate Creators:
  University of Wyoming. Dept. of Civil and Architectural Engineering
• Corporate Contributors:
  United States. Federal Highway Administration
• Subject/TRT Terms:
  • Rural highways
  • Variable speed limits
  • Highway safety
  • Compliance
  • Evaluation
  • Highway corridors
• Publication/ Report Number:
  FHWA-WY-13/03F
• Resource Type:
  Tech Report
• Geographical Coverage:
  Wyoming
• Corporate Publisher:
  Wyoming. Dept. of Transportation
• Abstract:
  The Wyoming Department of Transportation (WYDOT) installed its first variable speed limit (VSL) corridor along ; Interstate 80 in the Elk Mountain Corridor in the Spring of 2009 in an effort to improve safety and reduce road closures, ; particularly during winter storm events. Since that time, four additional variable speed limit corridors have been ; implemented; three additional corridors along segments of Interstate 80 and one on WY 28, a rural two lane highway ; through the area of South Pass. There were three main objectives to this research effort: develop control strategy for the ; operation of VSL corridors, analyze the safety effects of the VSL system, and determine the impacts of the VSL on driver ; speed behavior. For the development of a control strategy, both weather and speed variables were considered. Initially a ; simple linear regression approach was considered but the complexity of the weather and speed behavior led to a regression ; tree based control strategy with a self-learning feedback loop using machine learning. For the safety task, descriptive ; baseline safety was analyzed for all five corridors. Since the Elk Mountain Corridor is the only VSL system in operation ; for more than two winter seasons, it was used for an Empirical Bayes (EB) before and after analysis, which indicated some ; statistically significant changes in crash frequency for just a few of the corridor segments. A weather-based safety analysis ; was performed on the four interstate VSL corridors and results from this analysis indicate a statistically significant ; reduction in crashes after the VSLs were implemented. Analyses of speed variables indicate a reduction in speed variation ; with the implementation of the VSL system. Modeling of the difference between observed and posted speeds show a ; reduction in speed compliance related to large reductions in posted speed limits.
  More +
• Format:
  PDF
• Funding:
  RS04(210)
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/29333/dot_29333_DS1.pdf
• File Type:
  [PDF - 20.76 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:4c03852a20d90d6eb1780d928caa9727491634ab78a53c5bd0b88d38c796097e