ACCIDENTS VERSUS WIDTH OF PAVED SHOULDERS ON CALIFORNIA TWO- LANE TANGENTS-1951 AND 1952

TWO-LANE RURAL TANGENTS WITH PAVED SHOULDERS WERE EXAMINED FOR THE RELATION BETWEEN SHOULDER WIDTH AND INJURY ACCIDENT RATE. IT WAS FOUND THAT THE ACCIDENT RATE TENDED TO INCREASE WITH SHOULDER WIDTH, EXCEPT AT TRAFFIC VOLUMES BELOW ABOUT 2000 VEHICLES PER DAY, WHERE THE TREND MAY BE REVERSED. THE EFFECT APPEARS TO BE CONTROLLED DIRECTLY BY SHOULDER WIDTH, RATHER THAN BY OTHER, ASSOCIATED, ROAD FACTORS. /AUTHOR/