At a glance
Cameras capture visual information, lidar measures with laser light, and radar uses radio waves. Their strengths differ. The safety and capability of a driving system depend on the whole implementation, not the presence or absence of one sensor.
Three kinds of evidence about the same road
This is a general comparison. Sensor design, placement, cleaning, software and the environment change what an actual vehicle can detect. Avoid applying a capability from a research demonstration to every car using that sensor type.
| Sensor | Useful information | Limits to consider |
|---|---|---|
| Cameras | Visual appearance, signs, signal colors and lane markings | Lighting, visibility and obstruction can complicate interpretation. |
| Lidar | Range measurements and three-dimensional geometry | Weather, dirt and reflective surfaces can affect measurements. |
| Radar | Object distance and motion using radio waves | A radar measurement alone does not explain every visual detail or road rule. |
Why combine sensors?
A fusion system uses multiple inputs to estimate the scene. If one view is uncertain, other evidence may help. Redundancy can be useful, but it must be designed and tested; a larger sensor count is not an automatic safety score.
Waymo describes cameras, lidar and radar working together. Its newer sensor design includes measures for weather and reflections. Tesla describes consumer FSD around camera-based vehicle perception. These are implementation choices, not enough evidence to rank overall crash risk.
Lidar maps are not the same as onboard lidar
A road may have been surveyed using lidar even when a consumer car does not carry a driving lidar sensor. Chevrolet describes Super Cruise using a mapped compatible-road network. The map and the vehicle’s live sensing have different roles.
Likewise, seeing a roof sensor on a robotaxi does not tell you its exact generation or operating rules. Check the manufacturer’s technical description and service domain.
What should a buyer compare instead?
- The driver’s responsibility and monitoring requirements.
- Supported roads, speed and weather conditions.
- Features enabled on the actual hardware and software.
- Relevant safety evidence with comparable conditions and clear limitations.
- Equipment and service costs for the capability you can use now.
Common questions
Does lidar work in darkness?
Lidar supplies its own laser light, so it does not depend on daylight in the same way as a conventional camera. That does not make it immune to weather, contamination or measurement errors.
Does a car need lidar to be autonomous?
A sensor list alone does not determine automation level. The relevant questions are what the system performs, within which conditions, and what the human must do.
Explore the related guides
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Understand Waymo’s Jaguar I-PACE and Ojai fleet, sensor technology, the Hyundai partnership and vehicle cost versus passenger fares.
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Self-Driving Car Glossary
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Sources & research
Based on the linked documentation. This is a research guide; availability, equipment and terms can change. Confirm the exact vehicle or trip with the provider.