The growth of light rail transit (LRT) systems running on city streets calls for a careful look at the capacities that are attainable. While there is considerable experience with conventional street car and rail rapid transit operations, there are relatively few analyses of the interactions among dwell times, signal timing, and street intersection spacing. This paper reviews street car and LRT operating experience. It then develops general approaches to capacity that build upon the basic relationships contained in the 1985 Highway Capacity Manual (HCM) for two basic conditions: (1) operations of conventional street cars and (2) LRT operating in trains. For the latter condition, it suggests that the capacity is the lesser of that based on signal green time, station dwell times, and train clearance times, and that based upon a maximum of one train every other cycle. (A)
Abstract