Using fuzzy clustering of user perception to determine the number of level-of-service categories for bus rapid transit

The concept of level of service (LOS) is meant to reflect user perception of the quality of service provided by a transportation facility or service. Although the LOS of bus rapid transit (BRT) has received considerable attention, the number of levels of service of BRT that a user can perceive still remains unclear. Therefore, this paper addresses this issue using fuzzy clustering of user perception. User perception is a six-dimension vector including perceived arrival time, perceived waiting time, bus speed perception, passenger load perception, perceived departure time, and overall perception. The research team developed a smartphone-based transit travel survey system to conduct the user perception surveys in three BRT systems in China. Fuzzy C-means clustering, improved using a simulated annealing genetic algorithm, was adopted to partition user perception into 2–10 clusters. Seven cluster validity indices were used to determine the appropriate number of LOS categories. The results indicate that users can perceive two to four levels of service.