BUSROUTE - public transport route information system using a GPS

摘要

Busroute is a very low-cost, in-bus public transport passenger route information system providing location information to onboard passengers. The system should be useful on routes populated by tourists who are not familiar with the area and the bus routes. The typical pilot system with an ordinary GPS, a standard laptop PC, the digital interface card, and a wallmap costs less than £2000. The unit cost of professionally-designed systems is expected to be much lower when many such systems are designed for a wider-scale application. The maintenance cost of the system is expected to be small since the electronic units used in the project can be obtained as standard off-the-shelf products. No changes to the wallmap are generally required since the bus routes and the positions of bus-stops on these routes do not normally change much. The position accuracy of the GPS can be improved by using differential GPS units, although this will increase the overall system cost considerably. There is a feeling that the U.S. Department of Defense will give up Selective Availability within the next few years. This will bring the NAVSTAR GPS accuracy down to ±30 metres. An alternative could be to use the Russian GLONASS satellite system which gives an accuracy to ±30 metres and is available to commercial users. This system is, however, more expensive since each satellite uses a different frequency.