PASSENGER CAR EQUIVALENCIES OF TRUCKS, BUSES, AND RECREATIONAL VEHICLES FOR TWO-LANE RURAL HIGHWAYS

Passenger car equivalents or adjustment factors for trucks, buses, and recreational vehicles are often required in carrying out highway capacity calculations. This paper presents, in part, the results of a research project into the effect that recreational vehicles have on highway capacity. Described are the underlying methods referred to in the 1965 Highway Capacity Manual for determining passenger car equivalents, the methods used for developing equivalencies for recreational vehicles, and the use of the new equivalencies for typical highway capacity computations. Sensitivity testing of a recreational vehicle simulator model is discussed. Results of the sensitivity testing, which was extended to include highway capacity computations, strongly indicate that the present passenger car equivalent speed curves and adjustment factors in the 1965 Highway Capacity Manual require further refinement and updating, particularly at slower speeds. This paper estimates their correct placement by applying basic traffic engineering relationships. /Author/