Speed Harmonization—Design Speed vs. Operating Speed.

Details

• Creators:
  Ouyang, Yanfeng ; Jiang, Zhoutong ; Jadaan, Khair
• Corporate Creators:
  Illinois Center for Transportation
• Corporate Contributors:
  Illinois. Department of Transportation. Bureau of Materials and Physical Research ; United States. Federal Highway Administration ; United States. Department of Transportation
• Subject/TRT Terms:
  • Design speed
  • Rural highways
  • Operating speed
  • Traffic safety
  • Geometric design
  • Crash exposure
  • Benefit cost analysis Safety impacts
  • design speed
  • operating speed
  • geometric design
  More +
• Publication/ Report Number:
  Research Report No. FHWA-ICT-16-019
• Resource Type:
  Tech Report
• Geographical Coverage:
  Illinois
• Corporate Publisher:
  Illinois Center for Transportation
• Abstract:
  When the actual operating speed on the roads exceeds the design speed, which is common on rural highways, the roadway design may become problematic from a safety point of view. This report presents a new methodology that summarizes the relationship between design speed and operating speed, as well as the safety impacts of various geometric elements. A comprehensive literature review and a series of interviews with Illinois county engineers were conducted to summarize the current roadway design and maintenance practices and their impacts on Illinois roadway safety. An integrated modeling framework that includes modules ; for (1) geometric design simulation, (2) operating speed‐profile prediction, and (3) crash rate prediction, is proposed. Based on this research, a benefit–cost analysis was also developed to quantify the economic benefits of various strategies for roadway safety ; improvement. All models were programmed into an Excel VBA‐based computer tool to facilitate decision making. The outcome of this project may be suitable for implementation in a wide range of application contexts.
• Format:
  PDF
• Funding:
  ICT Project R27-SP30
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/31546/dot_31546_DS1.pdf
• File Type:
  [PDF - 2.85 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:e245b39ccca9aef7ad61bf2f72ebb2131ab9d11a2f0dc661be1bb5d87089b7e2eb391ec50474b2e787163a41f92b73f2ef77074e50b2d541376f5e9cc639fc25