April/May 2002

Everyone accepts that traffic congestion is going to get worse over the next few years. So adding real-time traffic information to a satellite navigation system could prove vital.

Siemens VDO Trading has become the first company to incorporate the new Traffic Message Channel (TMC) into its two navigation systems, VDO Dayton and Philips CARiN. Traffic data is relayed to drivers via RDS TMC, a digital data stream carried in the UK by radio broadcaster Classic FM. Owners of TMC-prepared radio-console navigation systems need only buy a new map disc containing a set of special location codes to enable the service. For operators with a screen-based system, Siemens VDO dealers can install an MT5000 interface and replace the old map with a TMC-specific one for a one-off charge of £150.

Data is supplied by ITIS Holdings, which has developed a system called Floating Vehicle Data System (FVDS). Vehicles actually on the roads, including National Express buses and Eddie Stobart trucks, all supply information on speed and position to ITIS, allowing accurate picture of actual road conditions to be calculated.

The system differentiates between different types of slow-moving traffic, such as whether caused by sheer numbers of vehicles on a road, accidents, fog or road works. TMC data can be used by the navigation system to plan alternative routes around incidents or congestion and to predict arrival times.