Author: B.L. Bowman

Date of Publication:  December 1985

Sponsoring Agency:  U.S. Department of Transportation - Federal Highway Administration, Office of Safety and Traffic Operations (R&D)

Performing Organization:  Goodell-Grivas, Inc.

Report No: FHWA/RD-86/156

Abstract:

The primary purposes of this study were to determine the extent of use, reasons for nonuse, and the effectiveness of constant warning time (CWT) systems. CWT systems consist of track circuitry and control logic capable of determining train speed, motion, and distance from the crossing. These parameters are used by the logic system to estimate train arrival time and to provide a uniform amount of advance warning at the railroad-highway crossings. The result is that motorists are not subjected to unnecessarily long delays before train arrival.

Analysis of operational data indicated that CWT systems are effective in both providing a uniform amount of advance warning and in reducing motorist violation of the warning system. A comparative analysis of vehicle-train accidents occurring from 1980 through 1984 was also performed. This analysis indicated that crossings with CWT systems, in the majority of cases, have a lower accident rate than crossings without CWT. This difference was not, however, large enough to be statistically significant at the 95 percent confidence level.

The study disclosed that some of the factors inhibiting the installation of CWT systems are based on perceptions of cost, dependability, and compatibility formed from problems with early CWT systems. Many of these problems have been resolved and are no longer prevalent in current models.
 

No. of Pages:  107