Traffic management in urban environment differs significantly from traffic management on highways. The major reason for this is the multiplicity of traffic participants and transport carriers, including pedestrians, bicycles, motorised private and commercial vehicles, public transportation by means of buses, trams, trains (metro), that either share transport paths, or of which the transport paths partly overlap. In addition to this complexity, self-driving vehicles, once introduced, will add further challenges for traffic management, including the need for electronic management of regulations and policies.
Urban traffic networks are of course not isolated. They have close connections to neighbouring networks, often multiple networks, whose characteristics might be similar or different: other urban authorities, rural roads, and interurban highways. Because urban networks tend to be geographically relatively small, the “boundary effects” are very important, and there is an increasing need for active and cooperative management of traffic across urban boundaries. This requires the exchange of detailed traffic management information, in real time, with other roads authorities.
Furthermore, road users increasingly have information about local traffic, through either fleet managers (for example, for freight vehicles or buses) or third party service providers (for private motorists). These too benefit from access to reliable traffic information to optimise their routing and travel behaviour. An urban authority will typically wish to encourage such intelligent use of real time traffic data: if traffic is informed of where congestion lies, it will tend to avoid routes that worsen the situation.
DATEX II is a mature and expansive suite of standards that specifies how data can be exchanged between roads authorities. However it has historically been aimed primarily at highways networks, and does not fully meet the requirements of urban authorities:
The objective of the project is expressed by the Prestudy Urban ITS:
Create a standard to enable seamless and vendor independent data exchange within and between ITS systems and services for multi-modal information services, synchronized traffic control, signage (road side and in-vehicle).
The scope of the project is to produce a CEN Technical Specification
Intelligent transport systems – Traffic Management Systems – TM interfaces and information
Defined as follows: