PASSING BEHAVIOR ON PUBLIC HIGHWAYS UNDER DAYTIME AND NIGHTTIME CONDITIONS

THIS STUDY WAS DESIGNED TO DETERMINE THE EFFECT OF NIGHTTIME VISIBILITY CONDITIONS ON THE PASSING BEHAVIOR OF DRIVERS ON TWO-LANE PUBLIC HIGHWAYS. THE EXPERIMENT WAS OBSERVATIONAL IN THE SENSE THAT THE DRIVERS WHOSE PASSING BEHAVIOR WAS OBSERVED HAPPENED ALONG FORTUITOUSLY AND HAD NO IDEA THAT THEY WERE TAKING PART IN AN EXPERIMENT, OR THAT THEIR PASSING BEHAVIOR WAS BEING OBSERVED. THE DATA WERE OBTAINED ONLY AT NIGHT, BUT AT THE SAME SITE AND UNDER IDENTICAL CONDITIONS IN WHICH DATA WERE COLLECTED DURING THE DAY IN A PREVIOUS FRANKLIN INSTITUTE CONTRACT WITH THE U. S. BUREAU OF PUBLIC ROADS. THE DAYTIME DATA FROM THE PREVIOUS CONTRACT ARE REPORTED ALONG WITH THE NIGHTTIME DATA IN THE PRESENTATION OF THE RESULTS. /AUTHOR/