The automatic creation of tactile maps on the basis of digital map data could improve their availability and the user-orientation. However, there is still too little support for this process mainly due to problems related to the creation of the map layout. Here, map generation using vehicle navigation data is discussed. Particular attention is paid to data visualisation. However, due to the size of the symbols the visualisation is not easily supportable by the use of computers.
Large symbols tend to clutter requiring map generation to solve the problem.
To meet the requirements for visualisation, a new approach to symbol displacement in the context of map generalisation is introduced - the Focus Line. This technique has been developed to displace symbols along streets and to achieve sufficient presentation space. Based on these techniques the system Map Wizard has been implemented for the semi-automatic creation of tactile maps using swell paper. Oxford OX1 3UD, United Kingdom. The Blue Mountain Eye Study Impact of visual impairment on use of community support services by elderly persons.