Articulated buses are being operated more frequently on popular bus routes, as they can handle higher passenger loads and increase rider comfort. Dwell and running times associated with articulated buses are expected to be different from regular low-floor buses. We use archived bus operation and passenger information from three heavily-used bus routes operated by the Société de Transport de Montréal, Canada, to measure these differences. Operation of articulated buses yielded to savings in dwell time, especially with high levels of passenger activity and the use of the third door in alighting. These savings were not reflected in running time, due to increases in the time associated with acceleration, deceleration, and merging with traffic. This study gives transit planners and operators important information on the differences in operating environments between regular and articulated buses.