Tesla Motors has come under heat in recent months because several vehicles using semiautonomous Autopilot systems were involved in accidents—some of which were fatal. In one well-publicized incident, a driver’s car crashed into a tractor trailer when it failed to recognize the white side of the truck against a brightly lit sky. However, authorities from the National Highway Traffic Safety Administration (NHTSA) determined there were no defects in the Autopilot or braking system; the driver had had seven seconds to react to the danger, but did not do so, likely due to distraction.

Autopilot should not be mistaken as a “self-driving” system. It is only semiautonomous, meaning Autopilot does not drive a car on its own; instead, it’s a limited set of features that—when used by an alert and defensive driver behind the wheel—allow the car to react to its surroundings to make driving safer. For example, the Autopilot system can gauge the speed of cars nearby and adjust cruise control speed, and it can do a small amount of automatic steering (the NHTSA found that crash rates dropped by almost 40% among cars able to keep themselves centered in a lane).

The NHTSA also found that among Autopilot-related Tesla crashes, many involved driver error, such as speeding, distraction and confusion over whether Autopilot was activated. Many crashes also occurred when Autopilot use was not appropriate, like when a driver was merging onto the highway or in heavy rain or traffic.

Even with Tesla’s latest software and hardware updates to its systems, drivers should always pay attention to the road and keep their hands on the wheel, just as they do when driving without Autopilot.