Driving tests

What is V2X and how can vehicles communicate with other technologies?

V2X means ‘vehicle-to-everything’. Its a set of technologies that enables a vehicle to communicate with other connected technology, and transfer power. The concept behind it is to improve road safety, fuel economy, and traffic throughput, and to spread the load on the electrical grid to improve resilience.

The various types of V2X technologies are:


Vehicle-to-vehicle, or V2V enables vehicles to exchange information directly with one another in real time, such as their direction, speed, position and type. Key benefits include:

Traffic flow optimisation – vehicles can share information about traffic flow so that navigation systems can reroute other drivers, vehicles can brake in anticipation of a snarl-up ahead, or jamitons can be reduced by careful speed management.

Collision avoidance – a vehicle’s movement is essentially a vector (a direction plus speed). Communicating this can allow other vehicles to interpret whether that might cause a collision, and therefore take evasive action.

Emergency alerts – if there is a crash, road closure or obstruction, or adverse weather, the vehicle may broadcast a warning. Emergency response vehicles such as ambulances may be able to be given quicker priority when it’s the vehicle that’s aware rather than the driver that has to become aware.

Traffic flow and cooperative manoeuvres – merging is a major cause of traffic congestion. Enabling the vehicles to manage the best merging speed and distances should improve traffic flow.


V2I enables vehicles to communicate with infrastructure related to the road, such as traffic lights, traffic management systems and so on. Key benefits include:

Traffic light optimisation – adjusting phases of traffic lights can help optimise traffic flow; there’s no point in a light remaining green when there are no vehicles going through it, especially at night where the phasing is not so critical for traffic management. This will improve fuel consumption by reducing idling time. Vehicles will also be able to adjust their speed accordingly, knowing whether a light is ‘stale’ as they approach; a stale light is one that will change before you get there.

Traffic management – as well as traffic lights, V2I can support other congestion-reducing measures such as opening or closing lanes. It may also be connected to railway level crossings and pedestrian crossings.

Infrastructure – vehicles may be able to talk directly with toll collection services, parking providers and electric vehicle charging stations.

Road condition – V2I can provide updates on the condition of the road up ahead, including construction zones and crashes.


V2P provides pedestrians, cyclists, and scooter riders information about nearby vehicles. This can be used for warnings about approaching vehicles where visibility might be limited (e.g. low light), assisting pedestrians at crossings, collision avoidance, and even things like approaching public transport options. It is especially useful for blind users.

Vehicle-to-grid and associated uses

As more and more people move from internal combustion engine vehicles to electric vehicles, the load on the power grid could become strained. V2G can use power stored in EV batteries to supplement power in the grid during periods of high demand, and vehicle-to-home can be used to power the home straight from the car battery. The basic concept is that EVs should be charged either at times of low power demand, when power is cheap, or when renewable energy is more available (e.g. solar). That stored power can be used for the benefit of the household at peak times rather than drawing from the grid, or it can be used to stabilise the grid to reduce the chance of brownouts.

An EV’s battery can also be used for vehicle-to-vehicle charging, powering farm equipment (V2F), other electric devices (vehicle-to-load) or building services (vehicle-to-building).

Are there any risks with V2X?

The main risks or drawbacks are:

  • Usefulness: V2X is only useful if all (or the vast majority) of vehicles are using it. It will be most useful in applications where all vehicles can be controlled by one entity, e.g. airport refuelling or passenger transfers.
  • Data: V2X creates a lot of data that needs to be transmitted and stored. Transmission and reception/decoding use power. Data may be stored in the cloud which has its own carbon footprint.
  • Weight: Adding more technology to vehicles simply increases the weight. Even if it’s not by much, aggregating it over tens of millions of vehicles adds up.
  • Security: protocols need to be hacker-proof otherwise there’s the risk that bad actors could take over functions of the vehicle.
driver training courses

Darren has written over 3000 articles about driving and vehicles, plus almost 500 vehicle reviews and numerous driving courses. Connect with him on LinkedIn by clicking the name above

Posted in Advice