1. A method of preparing map information for use for displaying maps on a mapping or navigation apparatus, the method comprising: receiving initial map information representing a map or maps to be displayed; performing, by a processor, a similarity analysis, the similarity analysis comprising analyzing map features within the initial map information to determine whether similarities exist between the map features based on shape and appearance when displaying the initial map information to identify one or more similarities within the initial map information; reducing, by the processor, the initial map information to generate reduced initial map information, the reducing comprising: selecting, based on the similarity analysis, one or more predefined map display elements, each predefined map display element being a shape template representing a corresponding shape to be displayed on a map constructed using the predefined map display element; and replacing, based on the similarity analysis, at least one selected map feature from the initial map information with a reference to the corresponding predefined map display element and one or more parameters, wherein the one or more parameters comprise an indication of a transformation to be applied to the corresponding predefined map display element when the corresponding predefined map display element is displayed; the reduced initial map information being a further representation of the map or maps to be displayed.