What are the key elements of a Telematics Application ?

Data acquisition

The quality and integrity of data will obviously affect the final quality of the telematics service. In some countries the public sector shoulders responsibility for the collection and processing of data, at the start of the information chain, in order to stimulate services and to retain responsibility for matters relating to road safety, traffic flow and road management.

Historically, traffic surveillance has been achieved through inductive loop detectors but new traffic sensor technologies are emerging which can be installed on overhead gantries and therefore are less disturbing to traffic flow. In Poznan, one of the latest detection techniques using video has been implemented, although there have been some teething problems. The traffic detection strategy will need to build on any existing systems and equipment and try to anticipate future requirements.

For many public transport applications – e.g. PT priority, fleet management, demand-responsive transport - information about vehicle location is important for both the individual driver, who needs to know where he or she is in order to navigate or to obtain location relevant data, and for the fleet dispatcher, who wants to track the vehicles for fleet management purposes.

Automatic Vehicle Identification (AVI) is used for tracking vehicles moving in an urban environment and there are several examples of beacon-based AVI systems in the case studies (e.g. Zlin, Southampton). Information derived through this process also forms the basis for real-time information displays at bus-stops and other transport nodes.

Data processing

On the infrastructure side another important data processing technology is automatic incident detection (AID). Thus in Cologne a variety of detectors provide input data to the strategy module which identifies the varying number of passing vehicles and assigns them to a decision scale. Depending on the details in the decision scale a text is taken from the text library which matches the current situation and displayed on the respective VMS.

Digital maps are a prerequisite for many transport telematics services. To create digital maps, the raw data need to be collected first from paper maps, aerial photographs, and other information sources. The information is then digitised, verified and updated from time to time. The next stage integrates this digitised map information with other relevant databases to form Geographic Information Systems (GIS).

Data communications

Although the traveller mass market has embraced the cellular and satellite-based data standards, other markets exist in specialised standards that are particularly appropriate to certain situations. Beacon-based communications, typically using short range frequency radio transmissions, are in widespread use for dedicated short range communications needs. These systems support electronic toll collection, commercial vehicle clearance, parking payment, in-vehicle signing, and a host of other applications. Beacons have even been used for fixed route bus services, where they provide cost effective real-time data communications services. In rural areas beacons now supplement visual hazard warning signs, providing the warning information directly to the driver's information system.

Any pre-existing telecommunications infrastructure should be integrated into the new transport telematics deployments as far as is practical in order to minimise costs while making new system data available to older applications. For example, many bus and emergency vehicles still make very effective use of mobile radio technology for communications with the dispatching and management centres. In these cases, gateways at central locations provide wired interfaces to the larger transportation information infrastructure.