Passing Activity on Two-Lane Highways in Spain

Abstract

Presented in this paper are the results of research on passing activity on two-lane highways in Spain. The data were gathered on three highways in the province of Madrid, Spain (M-111, M-600, and M-607). Measurements were carried out in 3-h periods, on plain or slightly sloping ground, and for daily or weekly peak periods. The average daily traffic and rate of heavy vehicles in 1991 were, sorted chronologically, 9,500 (6.4 percent) on the M-607, 9,800 (5.1 percent) on the M-600, and 8,100 (8.6 percent) on the M-111. Passing maneuvers were accounted for by examining the differences in order of vehicles at entry and exit points for each road section. A total of 780 passing maneuvers were detected. Passing rates were studied, in particular the variation of passes made with flow rates, both in the direction of passing and in the opposing direction. Maximum passing rates are suggested for each opposing flow rate, and it is indicated that passing is most effective for balanced flows of between 500 and 700 veh/h.