On-Board to Infrastructure 



These systems are vehicle initiated and communicate with the Infrastructure



Automatic Crash Notification/ TPS eCall

Automatic system to provide data notification to public safety answering points, by means of any available wireless communications media, that a vehicle has crashed, and to provide coordinates and other relevant information in a message of standardized data concepts, not limited in length. Information is transmitted via an ITS communications interface.


In Europe there is a system being introduced by regulation called eCall (see below) which does not involve a third party service provider. however "third Paty Assisted" eCall (TPS eCall" is also allowed from commercial service providers.

Blind Merge Warning

Provision of warnings from vehicles using the road network to other vehicles using the road network  to where highways or lanes merge. Such systems monitor the position of another vehicle approaching a roadway lane in front of the monitoring vehicle and communicate to warn the driver of that vehicle whether it is safe/ unsafe to change lanes or merge into a line of traffic. These systems are forward-looking, usually radar-based systems. Information is transmitted via an ITS communications interface.


A post event user instigated or automatic system to provide notification to public safety answering points, by means of wireless communications, that a vehicle has crashed, and to provide coordinates and a defined minimum set of data. Some eCall systems provide a voice channel communication with data attached, others are envisaged to use data communications with the possibility of VOIP. eCall systems use cellular communications to transmit their message/enable voice communications.


In Europe, 112-eCall  (a direct communication using 112 emergency channels and prioritisation) is now a mandated and regulated requirement for all new light vehicle models from 2018, although Third Party Assisted eCall (usually from providers of a wider basket of services to  drivers) is allowed (at the choice of the of the vehicle owner/driver) (See ACN above)

Incident Mapping and Warning

Collection and collation of data from vehicles to assist in the mapping and management of incidents.

Intelligent Traffic Light Pre-emption for Priority Vehicles

A variant of Emergency Vehicle Signal Preemption  (see Emergency Vehicle Signal Preemption above)  where the preemption is not limited to emergency vehicles, but may provide priority to other defined calluses of vehicles, such as public transport, HOV (over single occupancy vehicles) etc.

Intersection Collision Avoidance

Intersection safety has begun to receive new attention from traffic engineers, human factors specialists, and others who see that emerging intelligent systems offer significant potential for improvements (Ferlis, 1999). Crossing path crashes at intersections, as defined by Volpe (Barr, 2001), involve one vehicle cutting across the path of another, both initially travelling from either perpendicular or opposite directions, in such a way that they collide. See Intersection Collision :  Infrastructure-Based Warning  and Intersection Collision :  Vehicle-Based Warning Information is transmitted via an ITS communications interface.

Intersection Collision :  Vehicle-Based Warning

The provision of warnings of potential collisions from vehicles to the infrastructure when approaching or at intersections (especially at blind intersections).


Such systems are said to be “cooperative”. Cooperative systems communicate information directly to vehicles and drivers. The major advantages of cooperative systems lie in their capabilities to improve the interface to the driver, and hence to virtually ensure that a warning is received. This could also take advantage of the potential to exert control over the vehicle, at least in situations where the system can be confirmed as reliable and the driver cannot reasonably be expected to take appropriate actions given the imminent hazard and response time available. Information is transmitted via an ITS communications interface.

Probe Data

Probe data is data collected by vehicles and shared with the infrastructure for probe data management (usually anonymously) using an ITS communications interface. Probe data can also be gathered by the external monitoring of the movement of vehicles (usually anonymously), for example to calculate average speed and predicted travel times to particular points en route. Traffic information from probe vehicles has great potential for improving the estimation accuracy of traffic situations, especially where no traffic detectors are installed. Probe data is fed into state equations in macroscopic traffic-flow models, and can be combined with stationary detectors.

Vehicle-Based Warning

This is a generic term covering a number of services where a vehicle is the originator of the warning. Information is transmitted via an ITS communications interface.

SOS Services

Provision of connections from vehicle to emergency services for the transmission of voice and/or data communications. May use an ITS communications interface or cellular communications.