Investigation and solution of bus bunching problem

Abstract

Buses of the same service route leave the interchange at the scheduled timings to maintain the required headway (in minutes) between buses. This headway differs for peak and non-peak hours. The public transport system this study will look into are both the public bus operator in Singapore, namely Singapore Bus Service (SBS) and Singapore Mass Rapid Transit (SMRT).

Buses are normally able to keep to the required headway for the earlier part of the service route after leaving the interchange. However, this headway is not maintained throughout the service route due to uncontrollable factors such as traffic and hazards. This eventually leads to bus bunching at the bus stops where more than one bus of the same service route arrives at the same bus stop although the buses left the interchange at the scheduled timings.

Bus bunching causes inconvenience to the commuters and affect the commuters’ level of satisfaction. It reduces the reliability of the bus service when the buses do not arrive on time. The number of commuters also increases significantly at bus stops which have late bus arrivals causing the commuters to squeeze onto the buses reducing the level of satisfaction.