Harnessing the Potential of Automated Data to Simulate Emissions of an Interregional Bus Route in Toronto,Canada

Abstract

This study made use of automated vehicle location and automated passenger counter data to simulate the greenhouse gas (GHG) emissions of an interregional bus route in Toronto, Ontario, Canada. The authors analyzed bus performance and emissions as well as quantified emissions under the effects of operational improvements (increasing speed and reducing idling) and different fuels (conventional diesel, compressed natural gas, and biodiesel). Average total trip emissions were 54 kg per bus, with emissions higher in the morning peak period than in the afternoon peak period. Emissions rates on the highway portion of the corridor were lower than emissions rates for the arterial portions, with mean values of 1,627 g/km and 1,993 g/km, respectively. The authors observed that the addition of each passenger influenced bus emissions per passenger differently; when the bus was less crowded, each additional passenger could decrease emissions per passenger by 7%, but that reduction becomes 1.3% when the bus is crowded. Finally, the study results estimated that operational improvements could reduce emissions by 22%, whereas switching to compressed natural gas without speed improvements could reduce emissions by 6%. The effects of emissions reduction strategies are highly dependent on the characteristics of the bus and drive cycle. These results are useful to transit planners in the selection of appropriate GHG reduction strategies as well as in the selection of candidate corridors (highway versus arterial routes) for fleet renewal.