Self-driving cars are electric vehicles built to operate with little or no human control, using sensors and software to navigate roads on their own

A self-driving car, also called an autonomous vehicle, uses cameras, radar, and lidar (a laser-based sensor) to see the road, detect other vehicles and pedestrians, and make driving decisions without a person at the wheel. Most self-driving cars in development are electric because electric motors are easier to control precisely than gas engines, and the quiet operation helps the car's sensors work better.

The technology exists on a spectrum. Some cars have Level 2 automation — features like adaptive cruise control and lane-keeping that handle specific tasks while you stay alert and ready to take over. Others are being tested at Level 4, where the car drives itself in defined areas (like a city or highway) with no human input needed. A fully self-driving Level 5 vehicle that works anywhere, in any condition, does not yet exist on public roads.

If you own or are considering an electric vehicle, understanding how self-driving features work helps you know what the car can and cannot do, and what your responsibilities are when the technology is active.

Key Takeaways

  • Self-driving cars use sensors and software to navigate without human control, and most are electric because electric motors respond faster and more precisely than gas engines.
  • Current vehicles on the road have partial automation (Level 2), not full self-driving; you must stay alert and ready to take over at any moment.
  • Even when a car has self-driving features, you remain legally responsible for the vehicle's actions and must follow all traffic laws.
  • Electric vehicles are better suited to self-driving technology because their simpler powertrains make it easier for computers to control acceleration, braking, and steering.

Why electric vehicles are the natural fit for self-driving technology

An electric motor responds to commands from a computer almost when ready, with no delay. A gas engine requires the computer to manage fuel injection, transmission shifts, and other mechanical steps that take fractions of a second longer. In self-driving, those fractions matter — the car needs to brake or accelerate with precision to avoid obstacles or respond to changing road conditions.

Electric vehicles also have a lower center of gravity because the battery sits in the floor, which makes them more stable when the computer is steering. The absence of engine noise and vibration means the car's sensors can pick up sounds and vibrations from the road and other vehicles more clearly, giving the self-driving system better information to work with.

Additionally, electric vehicles produce no exhaust and run quietly, which is important for testing self-driving cars in populated areas. A silent car is less distracting to pedestrians and other drivers, and it allows the vehicle's microphones to listen for sirens, horns, and other audio cues that help it understand what is happening around it.

How self-driving sensors and software actually work

A self-driving car uses multiple types of sensors working together. Cameras capture what the car sees — road markings, traffic lights, pedestrians, and other vehicles. Radar bounces radio waves off objects to measure their distance and speed, which is especially useful in rain or fog when cameras struggle. Lidar fires laser pulses and measures how long they take to bounce back, creating a detailed 3D map of everything around the car.

The car's software — often called the autonomous driving system — takes all this sensor data and runs it through machine learning models trained on millions of miles of driving footage. The software predicts what other road users will do next, plans a safe path forward, and sends commands to the electric motor, brakes, and steering. This happens dozens of times per second.

The system also uses GPS and high-definition maps to know where it is and what the road layout should be. If a sensor detects something unexpected — a pothole, a fallen tree, a person in the road — the software can either navigate around it or, if the situation is too uncertain, hand control back to the human driver or bring the car to a stop.

The difference between partial and full self-driving

Most electric vehicles you can buy today have Level 2 features — systems like Tesla's Autopilot, Cadillac's Super Cruise, or BMW's Driving Assistant. These handle highway driving or traffic jams by keeping the car centered in its lane and matching the speed of traffic ahead. But the name is misleading: you must keep your hands on the wheel, eyes on the road, and be ready to take over when ready. The car cannot make turns, navigate city streets, or handle unexpected situations.

Companies like Waymo and Cruise are testing Level 4 vehicles in specific cities. These cars drive themselves in defined areas — downtown San Francisco, parts of Phoenix — without a human driver. But they do not work everywhere; they have been trained on those specific roads and conditions. If you took a Level 4 car outside its mapped area, it would not function.

A Level 5 vehicle — one that drives itself anywhere, in any weather, on any road — remains theoretical. The technology to handle every possible scenario does not yet exist, and it may take many more years to develop.

What you are responsible for when using self-driving features

Even if your electric vehicle has advanced self-driving features, you are legally responsible for the car's actions. If the car hits someone or causes an accident while a self-driving feature is active, you can be held liable. This is true even if you believe the system made a mistake.

When using Level 2 features, you must stay alert. The system can fail without warning — a sensor can be blocked by dirt or rain, the software can misinterpret a situation, or the car can encounter a scenario it was not trained for. You need to be ready to take control in seconds. Looking at your phone, eating, or sleeping while Autopilot is on puts you and others at risk and violates the terms of use for these systems.

Before using any self-driving feature, read your vehicle's manual to understand exactly what it can do, what conditions it needs to work, and what you must do to stay safe. Different manufacturers have different rules about when you can use their systems and what they are responsible for.

The current state of self-driving electric vehicles on the road

As of now, no fully self-driving electric vehicle is available for purchase by the general public. Waymo operates a robotaxi service (a self-driving taxi with no human driver) in parts of San Francisco and Phoenix, but you cannot buy or own the vehicle. Cruise, owned by General Motors, has paused its robotaxi service in most cities as of 2024.

What you can buy are electric vehicles with Level 2 features. Tesla offers Autopilot and Full Self-Driving (a subscription that adds more features but still requires human supervision). Cadillac's Lyriq and Escalade IQ have Super Cruise, which handles highway driving hands-free in certain conditions. BMW, Mercedes, and other manufacturers are adding similar systems to their electric models.

The gap between Level 2 and Level 4 is enormous. Level 2 systems handle repetitive tasks on highways; Level 4 systems must navigate city streets, handle construction zones, interact with pedestrians, and make judgment calls in ambiguous situations. Closing that gap has proven much harder than early predictions suggested, and timelines for widespread Level 4 deployment keep shifting.

How self-driving technology affects your driving experience and safety

If you own an electric vehicle with Level 2 features, self-driving technology can reduce fatigue on long highway drives and lower the risk of accidents caused by human error like drifting out of your lane or failing to notice a car ahead slowing down. Studies show that well-designed automation can prevent certain types of crashes.

However, these systems can also create a false sense of security. Drivers sometimes trust the automation more than they should and stop paying attention. The system then fails in a situation the driver could have handled, but the driver is not ready to respond. This is why manufacturers emphasize that you must stay engaged and alert, even though the car is doing the driving.

As self-driving technology improves, the experience will change. If Level 4 vehicles become common, you may be able to read, work, or rest during your commute. But we are not there yet, and the transition period — where some cars are partially self-driving and others are not — requires extra caution and clear understanding of what your specific vehicle can do.

Frequently Asked Questions

Can I sleep or use my phone while my electric car is driving itself?

No. Even if your car has advanced self-driving features, you must stay awake, alert, and ready to take control. Level 2 systems can fail without warning, and you are legally responsible for the car's actions. Using your phone or sleeping while the car is driving violates the terms of use and puts lives at risk.

Are self-driving electric cars safer than regular cars?

Self-driving features can prevent certain types of accidents, like lane-drift crashes and rear-end collisions. But they also introduce new risks — drivers who trust the system too much and stop paying attention, or situations the software was not trained to handle. Overall safety depends on how well the system is designed and how carefully the driver stays engaged.

How much does it cost to add self-driving features to an electric vehicle?

Some Level 2 features come standard on certain electric vehicles. Others are optional packages that cost thousands of dollars upfront, or subscriptions you pay monthly. Tesla's Full Self-Driving subscription, for example, costs around $200 per month, though prices vary by region and change over time. Check your vehicle's pricing details for exact costs.

Will my electric car drive itself on city streets?

Current Level 2 systems work mainly on highways and in traffic jams. They cannot navigate city streets, make turns at intersections, or handle complex urban driving. Only Level 4 vehicles in specific cities (like Waymo in San Francisco) can drive themselves on city streets, and those are not yet available for purchase.

What happens if the self-driving system fails while I am driving?

The system will alert you and ask you to take control. You have a few seconds to respond. If you do not take over, the car will slow down and eventually stop. This is why you must stay alert and keep your hands ready — the handoff from the car to you needs to happen quickly and safely.