This paper reports an empirical study of saturation flows and passenger car equivalents at signalised intersections in Hong Kong. Data were collected on 19 road sites in Hong Kong. The sites consisted of one-lane, two-lane and three-lane approaches. The results of calibrating a mathematical relationship between saturation flow and relevant factors are presented. The factors of the saturation flow to be included in the calibrated model are lane width, radius of turning, proportion of unopposed turning movement, and traffic composition. The proposed model is compared with the saturation flow equations being used in practice (Transport Planning and Design Manual of Hong Kong Transport Department). The passenger car equivalents for different types of vehicles are also tested against field data. It was found that the measured passenger car equivalents and saturation flows are generally smaller than those being used in the United Kingdom as the site characteristics and driver behaviour in Hong Kong are different from those in developed countries. (A)
Abstract