easy-City: a route search system for public transport users

This paper addresses the hard problem of route searching on public transport transportation. easy-City is a decentralized collaborative system that takes advantage of public transport users' mobility and observations to provide a route searching service. Users' mobile phones and deployed infra-structure devices establish a delay-tolerant network to efficiently disseminate information about routes and other events occurring on the public transportation network. We introduce a novel message dissemination protocol that exploits estimates of each user's future locations to make informed forwarding, message aggregation and buffer management decisions. A simulation-based evaluation of easy-city with geographical and public transport data shows that, in a realistic scenario, the system aids users to find best route options even in the presence of unpredictable events. A simulation with 468 nodes shows that easy-City often provides better options than a typical journey planning application based on static knowledge about the transportation network.