THE EFFECTS OF WIDE EDGE LINES ON LATERAL PLACEMENT AND SPEED ON TWO-LANE RURAL ROADS

The results of an evaluation of effect of edge lines 4 in. and 8 in. wide on the lateral placement and speeds of vehicles on two-lane rural roads are presented. Data were collected at 12 locations on sections of roadway covering 55.2 mi. It was concluded from analyses of variance of lateral placement, lateral placement variance, encroachments by automobiles and trucks, mean speed, and speed variance that, overall, there were no statistically significant differences between the 4-in. and 8-in. wide edge lines. The mean lateral placement was significantly lower for the 8-in. line. However, changes in lateral placement and speed were not significant from a practical viewpoint.