In this guide
Short answer: a Waymo uses lidar, cameras, radar and microphones to build a 360-degree picture of everything around it, then its AI software works out where it is, predicts what other road users will do and decides how to drive. Nobody drives it remotely. When it gets stuck, it can ask a remote human for advice, but the car still does the driving.
Waymo calls its self-driving system the Waymo Driver: the same hardware and software, fitted to different vehicles. Here's how it works in plain English, from the sensors on the roof to the people in the control room. For whether it's safe, see is Waymo safe?
The sensors: what the car "sees"
| Sensor | What it does | Good at |
|---|---|---|
| Lidar | Spins laser beams to build a 3D "point cloud" of the surroundings | Exact shape and distance of everything, day or night |
| Cameras | High-resolution images all around the car | Traffic lights, signs, colors, hand signals |
| Radar | Radio waves that measure distance, speed and size | Rain, fog, glare and fast-moving cars |
| Microphones | External audio receivers on the roof dome | Sirens and railroad crossings, often before they're visible |
The sensors overlap on purpose. If one is blinded, for example a camera facing the low sun, the others still see. That's the main difference from Tesla, which relies on cameras alone (see Tesla Robotaxi vs Waymo).
On the newest version, the 6th-generation Waymo Driver used in the Ojai vehicle, Waymo says the cameras are sharper (17-megapixel) and fewer than half as many as before, and the sensors have heaters, wipers and cleaning systems for rain and snow. Reported counts for the Ojai are 13 cameras, 4 lidars and 6 radars, against 29 cameras and 5 lidars on the older Jaguar.
The software: from seeing to driving
- Where am I? The car matches what it sees against detailed maps of the service area to know its position down to the lane.
- What's around me? AI models combine all the sensor data to identify cars, cyclists, pedestrians, cones, open doors and debris.
- What will they do next? The software predicts the likely path of everything nearby: the cyclist who might swerve, the car that might cut in.
- What should I do? It plans a safe, smooth path, many times per second, and controls steering, braking and speed.
All this runs on computers inside the car, not in the cloud, so it keeps working if the mobile connection drops.
Remote assistance: the "phone a friend"
When a Waymo meets something it can't work out, such as a police officer waving traffic through or a road blocked by a fallen tree, it can ask a remote agent for guidance. Waymo's chief safety officer described this to the US Senate in 2026 as "phone a friend":
- Agents give context and suggestions, such as confirming that a lane is closed.
- They don't steer, brake or accelerate, and the car can reject a suggestion.
- They don't watch every car continuously; the car calls them when it needs to.
- Agents are licensed drivers with background checks, based in the US and abroad, including the Philippines. That last point drew criticism from some senators.
Separate from this, Rider Support is the team you talk to from the car's screen or the app if you need help during a ride. See Waymo customer service and lost items.
Why it only works in some places
Waymo maps and tests every area before riders can use it, then opens it gradually: first employees, then invited riders, then everyone. Freeways, airports and bad weather each get their own approval. That's why your Waymo may refuse a destination one street outside the boundary. The current map for each city is in Waymo cities.
What it can't do (yet)
- Heavy weather: service can be paused during floods and severe storms. See Waymo hours and weather.
- Construction zones: in May 2026, Waymo paused freeway trips after its cars missed ramp closures, and updated the software on its fleet.
- Anywhere, anytime: it only drives inside mapped service areas.
Frequently asked questions
How does a Waymo see the road?
With three kinds of sensors working together: lidar (lasers that build a 3D map of everything around the car), cameras (color, signs and traffic lights) and radar (speed and distance, even in rain and fog). Microphones also listen for sirens.
Is someone driving a Waymo remotely?
No. When a Waymo meets a situation it can't resolve, it can ask a remote agent for guidance, such as which way to go around a blockage. Waymo says these agents don't steer, brake or accelerate, and the car can reject their suggestions.
Does Waymo use GPS?
Yes, but not only GPS. Waymo also uses detailed maps of its service area and matches what its sensors see against them to know exactly where it is, down to the lane.
Why does Waymo only work in certain areas?
Waymo maps and tests each area before it lets riders in, and checks local conditions like weather, freeways and airports. That's why each city has a service area and expands gradually.
Update log
- Guide published, including the 6th-generation Waymo Driver and Waymo's 2026 Senate testimony on remote assistance.
Sources and official texts