Conventional traffic policies including TDM have attempted to switch commuters' transportation mode from the motorcar to public transportation mainly focusing on their outgoing trips. However, when commuters choose transportation modes for accessing the destinations, they consider not only the traffic service hours for their outgoing trips but also conditions for the return trips. The departure time of the final transport service and the number of bus services for evening hours are supposed to specially influence them to determine the transportation mode for their return trips. Suppose a case that although a person really wants to go to his office by bus, he cannot help commuting by car because the departure time of the last bus service for his return trip is too early for him. To promote TDM policies to minimize motorcar traffic, transport planning considering commuters' convenience in their homeward trips is necessary. The number of public bus users is being decreased year by year due to motorization development, which has seriously aggravated public bus earnings, meanwhile improvement of the level of public transport service is being demanded. Further the regulation of supply-demand adjustment of public bus services in Japan was abolished in 2002, and it realized free entry to bus service business and bus operators' discretional abolishment of bus lines. The residents have been concerned if the bus deregulation might result in deterioration of the service quality level, specifically in discontinuance of unprofitable lines and a decrease in the no. of bus services. However, bus service businesses should be managed considering not only profitability but local needs as well. Factors that are predominantly influential on users' evaluations on bus service quality are the service schedule, no. of services, and operation routes. Efficient bus service operation planning that takes into consideration local needs for these factors is indispensable toward the future. This study focused on commuters' return trips whose details have not been fully identified, and through commuter's attitude surveys investigated co-relations between bus service availability improvement for commuters' return trips and their selection of transportation modes. Further, this study analyzed users' evaluations on bus service quality by the improved window method that applies DEA to identify efficiency values of the bus services by district and bus operation schedule for return trips. JFL classification: C0, H0