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Center for Advancing Research in Transportation Emissions, Energy, and Health (CARTEEH)

A USDOT University Transportation Center

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FREEVAL-RL

FREEVAL-RL is a more sophisticated analysis tool that is able to test the reliability impacts of projects by dynamically modeling multiple combinations of demand and operating conditions along a corridor using a Monte Carlo simulation (i.e., repeated random sampling). The tool allows users to model up to 70 highway segments along a single corridor.

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

The FREEVAL-RL algorithm uses a number of factors to estimate the travel time reliability. These include:
– The number of lanes on the road
– The average speed on the road
– The standard deviation of speeds on the road
– The length of the road
– The traffic volume on the road
Based on these factors, the algorithm calculates an expected travel time and a reliability index. The expected travel time is simply the average speed multiplied by the length of the road. The reliability index is a measure of how close the actual travel times are to the expected travel time; a higher reliability index indicates that the travel times are more reliable.
In addition to these factors, FREEVAL-RL also takes into account the type of road (highway, urban, etc.), the time of day, and the day of the week. These factors can all affect travel time reliability.