1. A method of creating map data, including search acceleration data arranged to increase the speed at which a route can be planned across an electronic map, the electronic map comprising a plurality of navigable segments, representing segments of a navigable route in the area covered by the map, comprising: dividing, by a processor, the map into a plurality of regions; processing, by the processor, the navigable segments in order to generate a bit vector for at least some of the navigable segments within a region of the electronic map, said bit vector comprising a plurality of bits, each indicating whether the navigable segment is part of a minimum cost route to one of the other regions; processing, by the processor, the generated bit vectors for the region in order to compress the data, wherein the compression includes computing the correlation of bits in the bits vectors and coalescing said bits according to the computed correlation; and displaying, via the processor, at least a portion of the map data.