A map data structure and method and system for obtaining geographic information. Raw map data is converted into map data structure by generating an attribute layer for each geographic attribute according to a defined line pattern and line width, and defining a bit-array of fixed bit-length for each element of a grid representing geographic coordinates, where a bit value of “1” is assigned if a respective attribute is present at the grid element location and a bit value of “0” is assigned if the respective attribute is absent. A map image depicting selected geographic attributes may be generated and displayed from map data structure, by sequentially scanning each bit in bit-array in descending order of priority, for each grid element of selected location, and if binary value of scanned bit is “1” then attribute layer associated with bit is displayed according to assigned color value if attribute selected for display.