The report reviews an experiment undertaken to examine the relative effectiveness of five pavement marking/signing sequences for informing motorists of passing and no-passing zones on rural two-lane roads. Treatments examined included: (1) standard pavement markings; (2) pavement markings plus standard regulatory signing; (3) pavement markings plus no-passing pennants; and (4) and (5) two combinations of regulatory signs and pennants. Data were collected on overtaking/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 both more observant of 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/informative sequences resulting in progressively more compliance with the marked zones.
Abstract