V2X technology: traveling more safely through the city

Urban traffic is often complex and confusing. Vehicles that are networked with the infrastructure and other road users can avoid many accidents. But how exactly does this work?

Whether or not a driver brakes in time or ends up in an accident is often a matter of milliseconds. This is especially true in city traffic, where constant attention is necessary: cars drive very close to one another, pedestrians walk out from between parked cars, bicyclists change lanes unexpectedly. Soon intelligently networked vehicles will be helping us react better and faster in such situations.

Not only can V2X technology give drivers precious milliseconds, it can also make the invisible visible. The ones who will benefit most from this are the most vulnerable road users in cities: motorcyclists, bicyclists and pedestrians. But how exactly does it work? “V2X is a term like ‘premium beer’ – it has many meanings,” says Jürgen Kunz, V2X expert in the Passive Safety & Sensors business unit at Continental. “Generally it means that we wirelessly connect vehicles with the infrastructure, other vehicles, and even pedestrians.”

Kunz and his colleagues concentrate primarily on direct vehicle communication, or dedicated short-range communications (DSRC). In Europe, the technology is known as ITS G5. Vehicles establish temporary networks with the surrounding environment. Using a transceiver, they can send and receive data in the 5.9 gigahertz Wi-Fi frequency. You can imagine it as being like your Wi-Fi at home: data is transmitted only when something is in range.

Continuous communication

But there is an important distinction between ITS G5 and your Wi-Fi at home: the service providers are cut out in direct vehicle communication. This has many benefits: for one, you are not bound by contract to a specific provider. Furthermore, the temporary networks work independently of each other. “Have you ever tried to send a WhatsApp message during the half-time break in a stadium?” asks Kunz. “Sending is often very slow because the network is overloaded.” This cannot be allowed to happen in direct vehicle communication.

Their major advantage is speed – a decisive factor for safety. In dicey situations, information must be exchanged with as little delay as possible. “With the help of technology, we can gain more reaction time,” says Kunz. “This can prevent accidents or at least reduce their intensity.” An example is emergency braking. Previously, if someone was driving behind a truck and a car in front of it suddenly braked, only the brake lights of the truck served as a warning. With V2X communication, the braking car would send the information directly to the cars behind it.

Direct communication enables vehicles to exchange a variety of information. “On the one hand, there is mandatory status data such as vehicle type, speed, direction of travel, and sensor information,” explains Kunz. On the other hand, there is situation data, such as the transportation of dangerous goods, as well as optional data, such as information about vehicle occupants or open doors.” Because the data packets are relatively small, this information can be exchanged continuously.

More safety for everyone

The enormous benefits this technology brings were demonstrated by the simTD field research project, a joint project of leading German automobile manufacturers, suppliers, telecommunications companies and research institutions. “SimTD has shown that driving safety already improves considerably at an install rate of just five percent,” Kunz says.

V2X’s particular strength is making the invisible visible: in addition to the warning received when other cars suddenly brake, details of approaching emergency vehicles can be transmitted before you even hear the sirens. The left-turn assist feature can warn drivers at intersections about cars that are not yet visible. “The technology could be used for communication between vehicles and traffic lights or traffic signs,” says Kunz. “We could thus optimize dynamic traffic flow.” All this will make transportation in our cities safer and more efficient.

But above all, those most vulnerable on the roads would be protected better as a result. “So many accidents with motorcycles could be prevented if they were more visible. They could send a warning that says ‘Look, I’m here’” says Kunz. The same is true for pedestrians. “There are various technical options to do this, such as with smartphones or cameras.” The progress being made in this area is considerable. “The question of how vulnerable road users can best be seen will be one of the hot topics in the near future.”

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