BUS-STOPS, CONGESTION AND CONGESTED BUS-STOPS

This paper discusses some issues involved in estimating the effects of bus-stops on delay to buses, their passengers and to other traffic. It starts by reviewing the current understanding of bus traffic behaviour, mostly oriented to the situation prevailing in industrialised countries where bus flows are low, congestion is generated by other traffic (particularly cars) and bus-stops do not create major problems. It then moves on to analyse the problems usually encountered in developing countries where the number of buses is much higher and they contribute to congestion at least as much as cars. In this case, the problem is a good deal more complex as there is increased interaction between buses, passengers and bus-stop layout and operation. A conceptual framework for these interactions and precise definitions of bus-stop capacity and delays are then developed. The generation of analytical expressions for these variables is limited because the underlying process is a complex stochastic one. Therefore, a computer simulation program has been written to model this behaviour and its structure and main features are described. The paper concludes with some results from this program and a few general conclusions.