In this study, we focused on a short-trip rideshare system including nonmonetary rewards supported by other-regarding preferences of altruistic drivers in a village community. A methodology for simulating various mechanism designs of the short-trip rideshare system was developed. Using numerical simulation, we studied ways to improve the sustainability of the system by providing informational guidance. As a result, we showed that a higher number of rideshare pairs were sustained by messages that shaped the expectations of driver candidates about the success of ridesharing. From our numerical example, we concluded that the conveyance of informational guidance by a system operator, which induced each driver candidate to take action towards their delayed matching in place of failure, was reasonable roughly three times out of ten to promote system sustainability from the perspective of both the number of rideshare pairs and the welfare level of all participants.