Energy Efficiency Intersection


The Energy Efficient Intersection service provides advice to optimise the way vehicles pass through an intersection. Both energy and emissions are saved by avoiding any unnecessary acceleration or braking by the vehicle driver. To reach this goal, a two-way radio communication system is used between the traffic light control unit and the equipped vehicles.

The information on traffic light status is transmitted from the traffic light control unit to the oncoming vehicles. Inside the vehicle the driver receives information on when the traffic light ahead will change, either in the form of a time countdown or as a speed advice. This information allows the driver to anticipate the next manoeuvre and to change his/her driving behaviour, for example by decelerating when a red light is to become green and thus avoiding an unnecessary stop.

When a vehicle has to stop because the traffic light is red, the EEI service can then send  advice to the driver on whether it is convenient to turn off the vehicle engine. Shortly before the light turns green, the driver is warned to restart the engine. This reduces not only the delay between the green light and the vehicle driving away, but also the chance that other vehicles behind in the same lane have to brake and accelerate again.

Information about the oncoming vehicles is detected by cameras on main roads and roadside stations at each equipped intersection and sent via a radio connection to the city’s traffic management centre, where traffic managers can take appropriate action, like send out messages to cooperative ITS roadside stations and variable message signs on ongoing events (roadwork, accident, queue, etc.) to alert the drivers as needed. This information includes details such as vehicle type (emergency, bus, truck), location, speed and other parameters. Heavy-goods vehicles or delayed public transport buses can be given green light priority to reduce the number of stops and, hence, travel time and emissions. Vehicles such as ambulances, firefighters’ trucks or police cars, which are in an emergency status, can send a message to other vehicles and road side stations, so that they can be granted  absolute priority by other drivers and by traffic managers, who may turn red traffic lights at the intersections ahead to clear their way as fast as possible.

Implementation of the service in:

Bordeaux, Copenhagen, Helmond, Newcastle, Thessaloniki, Verona, Vigo

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