Author:  Eugene R. Russell

Date of Publication:  August 1974

Sponsoring Agency:  Indiana State Highway Commission

Performing Organization:  Joint Highway Research Project, Civil Engineering Building, Purdue University

Report No:  JHRP-74-16

Abstract:

The objectives of this research were to analyze the effect on motorists of improving the warning devices at a high-accident, rural grade crossing, from 8-inch flashers to automatic gates and 12-inch flashers activated by a Marquardt speed predictor and having additional strobe lights: to evaluate suitable parameters to make the analysis; to study accident history and site conditions and relate these to motorist reaction to the system - before and after; and to evaluate the data collection system itself.

Spot speeds were taken at eight points on each approach to obtain an approach speed profile for various groups under various conditions after the signal system was improved.  These were compared to similar data taken before system improvement.

It was shown that an activated gate arm can be as effective in slowing the average approaching vehicle as a train across the road.  Train and signal conspicuity were a problem and contributed to the poor accident record of older drivers.  The strobe lights made the warning system more visible after activation.

Most drivers approach a grade crossing safely and mean speed of various groups shows trends but it is a relatively weak parameter to test effectiveness, because they do not isolate the occasional unsafe driver.  Percent reduction of fastest cars, along with examining individual "fastest" cars, is a better parameter than mean speeds and decelerations to show improved effectiveness.

No. of Pages:  233