The proportion of time during which pedestrians can cross a two way road at a location inbetween two signalized intersections depends on the arrival time at a point of crossing of vehicular platoons released by the signals. Thus crossing capacity depends on the offset between signals. The same consideration applies to vehicular traffic which emanates from sideroads and exits or is destined to entrances inbetween the signalized intersections. A simple method is suggested allowing determination of optimal signal offsets for given exit or crossing locations (or alternatively, optimal exit locations for a given signal offset). The solution method is based on the time honoured but simplistic "band" representation of traffic streams. To examine the results of analysis under more realistic conditions, observations were conducted to describe the behaviour of groups of vehicles turning left from a sideroad into the mainroad traffic and the results are used in a simulation routine which allows for platoon dispersion and right turns against red. This semi-empirical validation tends to confirm the main results derived from the simple model. (a) for the covering abstract of the symposium please see irrd abstract no. 224453.
Samenvatting