Development of a prototype GIS based application for production of a route sketch map

Abstract

Current sources of digital route maps, such as those online, serve the requested route by way of highlighting the route on an otherwise normal (constant scale) road/street map of the area that contains the route of interest. Thus features both far from and near to the route are displayed. Within a limited display this presents clutter that reduces the effectiveness of the map. Also, short route sections necessary for navigation may become too small to be noticed following a reduction of scale by a uniform or constant scale. A solution is found from use of sketch maps which employ variable scaling in order to enhance features that would otherwise be too small to detect or correctly interpret and they are selective. The aim of the project was to prepare a prototype GIS based application that automatically constructs a route map in a sketch map format for display in limited sized display media that are increasingly common, for example, print-outs on A4 sized paper and displays of hand held devices e.g. mobile phones. In the project only print-outs on A4 sized paper as the display media were considered. Creation of the route sketch map was done by applying approaches similar to those of conventional map generalisation mainly line simplification and enhancement. Challenges exist in the process resulting from, mainly, the constraints of, having to confine route objects (symbols used) within set boundary extents and preserving original topology. A method that involved modelling a route-object as a series of chained vectors was used to ensure these constraints were addressed.