Abstract

An isochrone in a spatial network is the minimal, possibly disconnected subgraph that covers all locations from where a query point is reachable within a given time span and by a given arrival time. In this paper we formally define isochrones for multimodal spatial networks with different transportation modes that can be discrete or continuous in, respectively, space and time. For the computation of isochrones we propose the multimodal incremental network expansion (MINE) algorithm, which is independent of the actual network size and depends only on the size of the isochrone. An empirical study using real-world data confirms the analytical results.