A method for displaying a map on a mobile client device. The method
includes storing map data on a server, the map data including road data
with respect to roads of multiple different road types. The server
determines a route from a starting point to a destination within an area
covered by the map data, the route including one or more route segments.
The server defines a corridor map including the route segments and the
roads of the different road types that are within different, respective
distances, determined by the road types, of the route segments. The
server downloads the road data with respect to the route segments and the
roads of the different road types included in the corridor map to the
client device. The client device, using the downloaded road data, renders
one or more images, each image comprising at least a respective portion
of the corridor map.