The paper presents initial findings from a recent TMR-ARRB project which aims to produce a methodology for estimating congestion costs associated with a range of road users and confirm this methodology through pilot case studies. The paper starts from a literature review, then proposes a methodology for estimating multi-modal congestion cost by considering excessive congestion delay and travel time reliability cost. It also provides main findings from two pilot case studies using data from automatic bus ticketing system (Go Card system) and STREAMS data.

The first case study found that the average excessive congestion cost for bus passengers per day was $44,013 for weekdays and $14,111 for weekends in March 2015 for the study site. The travel delay cost was the largest contributor to total congestion cost, followed by passenger waiting time cost and travel time reliability cost. The second case study revealed that the multi-modal congestion cost methodology is feasible for freeway data analysis. It showed although the average daily VKT increased by 5% between the before-and after-periods of the study, the cost of congestion was reduced by 26% on a typical weekday during morning peak. A bulk of these cost-savings originated from reduced excessive delay cost, which experienced a 39% reduction. The travel time reliability cost also dropped by 7%.