COMPARISON OF SIGNS AND MARKINGS FOR PASSING AND NO-PASSING ZONES

An experiment was undertaken to examine the relative effectiveness of five pavement marking and signing sequences for informing motorists of passing and no-passing zones on rural two-lane, two-way rural roads. Treatments included (a) standard pavement markings, (b) pavement markings plus standard regulatory signing, (c) pavement markings plus no-passing pennants, and (d) and (e) two combinations of regulatory signs and pennants. Data were collected on overtaking and passing vehicles by two observers in a staged vehicle that traveled over a measured length of roadway. The principal findings were that the addition of any sign sequence to pavement markings resulted in motorists being appreciably more observant of the passing and no-passing zones and spending less time in the passing (opposing) lane. Less conclusive evidence was presented in support of the more emphatic and informative sequences that resulted in progressively more compliance with the marked zones. (Author)