Assessing the Social Costs of Mixed Transport Systems with a Dominance of Motorcycles

When undertaking strategic planning to identify potential options for a detailed assessment, it is important to compare the total costs of existing mixed transport systems with the introduction of different new public transport (PT) modes. Hence, this study develops a social cost model for situation of mixed transport system which has a dominance of motorcycles where a new PT technology (e.g. Bus Rapid Transit - BRT, Monorail or elevated Metro) or an exclusive bus lane is being considered. The innovative aspects of this research are to develop equations to estimate the average operating speed of each mode and to the allocation of infrastructure costs to several transport modes sharing the facilities in motorcycle dominated mixed traffic environments. Based on a four-lane per direction mixed traffic corridor in Hanoi, Vietnam, the results show the lowest average social cost (ASC) mixed transport systems for different ranges of demand. Moreover, all mixed traffic options with BRT, Monorail, elevated Metro or exclusive bus lanes are better than the existing situation in terms of ASC and it is suggested that their feasibility is examined in a detailed assessment. The mixed transport social cost model can be modified to suit other local conditions where conventional bus, car and motorcycle share facilities and a new PT mode is operated. Additionally, transport planners and decision makers in such local situations, which are particularly common in South East Asia, can draw on the findings of this study.