Effect of Vehicle Size on Highway Capacity in Thailand

Abstract

Paper presents the results of a study undertaken to determine the capacity of an uninterrupted‐flow highway in Thailand. The effect of the size of vehicles on the capacity is also investigated. Passenger car equivalents (PCEs) for medium‐ and large‐sized vehicles are calculated. It is found that the value of basic capacity was 2,180 passenger cars per hour per lane (pcphpl), which represents an increase of 9% above the value of 2,000 pcphpl currently being used in Thailand. The overall effect on the capacity with the prevailing proportion of large‐sized vehicles is a capacity reduction on the order of 15%. PCEs for medium‐ and large‐sized vehicles are obtained as 1.0 and 1.5, respectively.