Adjusted Minimum Time-to-Collision (TTC): A Robust Approach to Evaluating Crash Scenarios

Driving simulators provide a unique environment for evaluating critical driving situations where there is a significant possibility of a crash. In these scenarios, a number of dependent measures have been used to evaluate the effect of various treatments or systems. Three such measures are minimum TTC, collisions, and collision velocity but each has inherent problems. When there is a mixture of collision and non-collisions, minimum TTC and collision velocity suffer from a restriction in range that results in non-normal distribution of data. Collisions are a categorical data source that requires the use of less powerful non-parametric statistics. This paper presents a composite measure that utilizes minimum TTC, collisions deceleration, and velocity to provide a more robust measure of driver performance in scenarios that result in collisions. This measure, adjusted minimum TTC, indicates how much spare time the driver had or how much sooner the driver should have begun responding to avoid the collision. It is calculated in the same manner as minimum TTC when no collision occurs, but when a collision occurs, adjusted minimum TTC is calculated based on the relative velocity at collision and the deceleration of the driver’s vehicle at collision and the deceleration of the driver’s vehicle prior to the collision. This paper documents the method for calculating this measure and demonstrates its utility with experimental simulator data.

  • Corporate Authors:

    National Advanced Driving Simulator

    University of Iowa, 2401 Oakdale Boulevard
    Iowa City, IA  United States  52242-5003
  • Authors:
    • Brown, Timothy L
  • Conference:
  • Publication Date: 2005


  • English

Media Info

  • Media Type: CD-ROM
  • Features: References;
  • Pagination: 9p
  • Monograph Title: Driving Simulation Conference, North America 2005

Subject/Index Terms

Filing Info

  • Accession Number: 01140758
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 28 2009 12:25PM