A USDOT University Transportation Center

Reliability Analysis Tool for Sketch Planning

The Reliability Analysis Tool for Sketch Planning is a spreadsheet designed to function as a sketch planning tool for highway capacity projects that have impacts on both travel time and reliability. The tool estimates total delay costs and disaggregates it into recurring delay (i.e., travel time delay that is due to speed slowdown) and non-recurring delay (i.e., delay that follows random traffic incidents – vehicle collisions and breakdowns).

This tool will help achieve the goal of the following objectives

  • Less Contamination
  • Less Emissions
  • Less Traffic Noise
  • Connectivity and Inclusion
  • Healthy Destinations
  • Less Traffic Violence
  • Active Transportation
  • Green Space

Estimation Technique

When estimating the travel time delay that is due to speed slowdown, the Reliability Analysis Tool for Sketch Planning relies on data from travel time surveys. This data is used to develop models that predict how traffic flow will be affected by changes in conditions such as weather, construction, and accidents. The travel time delays that are predicted by these models are then used to estimate the reliability of a given route.