Vehicle-to-Everything (V2X) Explained: How Self-Driving EVs Talk to the City

Self-driving EVs don't rely on cameras and radar alone. Through Vehicle-to-Everything (V2X) they talk directly to traffic lights, other cars and the cellular network. Here's how the technology works and what it means for tomorrow's traffic.

What V2X Actually Means

Anyone who digs into self-driving technology eventually runs into the term Vehicle-to-Everything, or V2X. It describes a car's ability to do more than rely on its own sensors: it actively communicates with everything around it, including other vehicles, traffic lights and road signs, pedestrians, and the cellular network. V2X isn't a single component sitting under the hood. It's an umbrella term for several communication channels that together add a whole new layer of perception to the vehicle.

The topic matters especially for today's electric vehicles, since many of the most advanced driver assistance and self-driving features tend to land in EVs first. If you're wondering why that's the case, our guide on why self-driving cars are (almost always) electric covers the background. The actual sensor suite of a self-driving car, meaning cameras, radar and lidar, only paints a partial picture of the surrounding world: it sees what's in its direct line of sight, and it hits its limits when something is blocked from view, the weather turns bad, or objects are simply too far away. You can read more about that classic sensor stack in how self-driving cars see: LiDAR, radar & camera. V2X picks up exactly where that leaves off, adding information relayed directly from other road users and infrastructure, which then gets merged with the raw sensor data, as explained in our piece on sensor fusion in self-driving cars.

Source: Engineer's Academy: Understanding Vehicle-to-everything (V2X) Communication

The Five Building Blocks of V2X Communication

The Engineer's Academy video does a good job breaking V2X down into several sub-categories, each aimed at a different communication partner for the vehicle. Together they form a web of information that goes well beyond what a single car's own sensors could ever capture on their own.

V2V: Vehicle Talks to Vehicle

With Vehicle-to-Vehicle (V2V), cars exchange position, speed and heading with each other in real time. That means a car can flag a potential collision risk, or the sudden braking of the vehicle ahead, before its own camera or radar has even registered what's happening. In heavy traffic or when vehicles are following closely, that head start can make the difference for safety. In practice: if a car three vehicles ahead brakes hard, that information can reach every following vehicle via V2V within milliseconds, long before the brake lights themselves come into view.

V2I: Vehicle Talks to Infrastructure

Vehicle-to-Infrastructure (V2I) connects the car to traffic lights, road signs and roadside sensors. A self-driving vehicle can, for instance, anticipate exactly when a light is about to turn red and adjust its speed ahead of time instead of reacting at the last second. That saves energy, cuts down on unnecessary braking and accelerating, and smooths out traffic flow overall. In Germany, several pilot cities are already fitting individual traffic lights with the transmitters needed for this, letting equipped vehicles receive the remaining time left on a green or red phase directly.

V2P: Vehicle Talks to Pedestrians

Vehicle-to-Pedestrian (V2P) detects pedestrians and cyclists, in part through the smartphones or wearables they're carrying. At intersections without a clear line of sight, say behind parked cars or buildings, this link can prevent accidents that a camera alone wouldn't catch in time. For children, cyclists, or people with visual impairments, who face some of the highest risks in traffic, V2P is considered one of the most promising additions to conventional sensing.

V2N: Vehicle Talks to the Network

Vehicle-to-Network (V2N) connects the car to cloud services over the cellular network. That link carries real-time traffic data, navigation information and software updates, continuously feeding the car up-to-date knowledge about its surroundings, even beyond the direct range of V2V, V2I or V2P. Unlike the other three channels, V2N isn't limited to a short-range link with a nearby partner. It works essentially anywhere there's cell coverage, which is exactly why V2N is the most widely deployed piece of V2X in today's vehicles.

• V2V: position, speed and heading shared between vehicles
• V2I: communication with traffic lights and roadside sensors
• V2P: detection of pedestrians and cyclists
• V2N: cloud connection for traffic data and updates
• Shared goal: extra perception beyond a vehicle's own sensors

DSRC vs. C-V2X: Two Paths to the Same Goal

None of this data can flow without an underlying transmission standard, and right now two approaches are competing for that role. DSRC, technically specified as IEEE 802.11p, works similarly to Wi-Fi and operates in the 5.9 GHz band. It was long treated as the default standard for V2X communication, and it's still the technology behind most of the V2X services actually running on German and European roads today, such as traffic-light and roadworks-warning pilots built on the related ITS-G5 standard.

C-V2X relies on cellular technology, meaning 4G and increasingly 5G, and it's the option a number of automakers, including BMW, are increasingly leaning toward for the long run, largely because it can piggyback on cellular networks that already exist and keep improving, whereas DSRC needs its own dedicated infrastructure built from scratch. In Germany and the wider EU, regulators have so far stayed officially technology-neutral rather than picking a winner, so DSRC/ITS-G5 and C-V2X continue to coexist, with C-V2X trials expanding alongside the ongoing 5G rollout. In markets like the US and China, the shift toward C-V2X has gone further and is more clearly favored, and several industry associations expect a similar shift to eventually play out in Europe too, though as of 2026 no European standard has been formally settled, and DSRC remains far more than a handful of leftover test beds.

Why V2X Matters for Self-Driving Cars

Self-driving vehicles are typically classified using the SAE levels, which describe the degree of automation involved, covered in detail in our guide on the SAE levels of autonomous driving explained. The higher the level, the more responsibility the system takes on, and the more it depends on reliable, redundant perception. That's exactly where V2X comes in: it delivers information no onboard sensor could ever pick up on its own, like what's happening around the next bend or which traffic light phase is about to start.

Systems like Mercedes Drive Pilot, the first Level 3 system on German roads, also increasingly benefit from a more connected environment, because higher automation levels demand more verified information, not less. V2X doesn't replace cameras, radar or lidar; it adds a communication layer that delivers information before it would even become visible or measurable to the car itself. How these different data sources get combined inside the vehicle is covered in detail in the sensor fusion guide mentioned earlier, while the question of how much a system actually decides on its own ties closely into the distinction between conventional driver-assistance features and true self-driving capability, a line we draw more precisely between ADAS and self-driving cars.

Looking Ahead: V2X as the Foundation of the Smart City

The real scale of V2X only becomes clear once you zoom out. When it's not just individual vehicles but entire fleets continuously exchanging data with traffic lights, roadside sensors and each other, you get the technical groundwork for coordinated, optimized city traffic. Our guide on how autonomous cars are reshaping future cities digs into what that could look like. It becomes especially relevant wherever autonomous fleets operate at scale, such as robotaxis, where charging infrastructure and traffic management have to work hand in hand, a challenge covered in our piece on robotaxi fleets and charging infrastructure.

For EV owners specifically, there's an interesting side effect: the same connectivity backbone that enables V2X also underpins more advanced concepts like bidirectional charging, where a vehicle doesn't just draw power but can also feed electricity back into the grid. Similarly, connected vehicles may eventually be able to locate and drive themselves to an open charging spot on their own, a concept explored in our guide on autonomous valet charging.

Before nationwide V2X infrastructure becomes reality, even in a market as advanced as Germany, a few hurdles still need clearing: consistent standards across automakers, continued 5G buildout in rural areas, and, not least, privacy questions around vehicles that are constantly exchanging location and movement data. What's already clear, though, is that V2X is no longer some distant future concept. It's steadily becoming a standard feature in vehicles already on the road today, and a key building block on the way to safer, better-connected, more efficient traffic.

Additional Video

For a deeper look at the infrastructure and industry side of the equation, this video from ST Engineering explains how 5G-powered Cellular-V2X networks are being built out to let self-driving cars communicate directly with traffic systems and city infrastructure.

Source: ST Engineering – How Cellular Vehicle-to-Everything (C-V2X) technology can shape the future of mobility?