Modeling Frequency of Using Informal Public Transport and Public Bus: A Case Study in Phnom Penh, Cambodia

For decades, informal transport modes such as Motodup and Remork can be commonly observed in the urban area of Phnom Penh. They play an important role as a major public transport for local travelers, even before the public bus was put into full operation in 2014. This study aims to investigate underlying factors that influence the frequency of using informal transport and public bus by considering traveler's socioeconomic variables, trip characteristics, and operational characteristics of each transport mode. Utilizing ordered probabilistic modeling, data is analyzed based on 483 samples collected from four main areas in Phnom Penh, i.e., CBD, educational, residential and suburb areas. Results indicate that students do not use Motodup frequently, but they would prefer Remork. Moreover, travel cost is seen to be the major factor that could reduce the likelihood of using Motodup and public bus; however, this variable is not found significant in determining the frequency of using Remork. In terms of commuters' attitudes, Remork and public bus passengers perceive comfort and availability importantly. The more important they value these two factors, the more frequent they would use such modes. Since the public bus is currently a highly promoted public transport, policy makers should incorporate the quality of comfort and availability, and should keep the bus fare low in order to increase the usage frequency.