Citation

Andrews WH. Public Roads 1987; 51(2): 25-35.

Copyright

(Copyright © 1987, U.S. Federal Highway Administration)

DOI

unavailable

PMID

unavailable

Abstract

A study is reported which examined available railroad-highway grade crossing signal hardware and sought ways to improve the brightness and uniformity of crossing signals without changing their cost, or complicating their maintenance. The study also developed and evaluated 7 design alterations and 3 maintenance aids. Two permanently focused signal units were designed and fabricated, and two hardware configurations employing commercial power were evaluated. An instrument for use in optimizing adjustable-focus signals was also developed. The following hardware elements were evaluated: an alignment scope to aid in proper signal alignment; quartz-iodide lamps to improve efficiency; antireflective roundel coatings to increase transmittance; a special-purpose photometer for measuring crossing signal and traffic signal flux; a small clip to prevent rotation of loosened roundels; and the application of a low lamp current between flashes to extend lamp life. All hardware was laboratory-tested and the signal hardware protypes were subjected to environmental and field tests.

Language: en