More and more car buyers in Pennsylvania and around the country are choosing vehicles equipped with sophisticated autonomous systems that are designed to prevent accidents and make driving easier, but a study published by the Insurance Institute for Highway Safety suggests that this technology may not be as capable as car manufacturers claim. IIHS researchers came to this conclusion after testing autonomous systems offered by Tesla, BMW, Mercedes-Benz and Volvo on both public roads and closed tracks.

The IIHS study, which was released on Aug. 7, may have been prompted by an accident that claimed the life of a Tesla Model X driver in March. Investigators discovered that the vehicle’s autopilot system failed to notice a tractor-trailer entering an intersection. Another highly-publicized incident occurred in May when an Uber SUV struck and killed a pedestrian in Arizona while testing an autonomous system.

The IIHS researchers said that they frequently encountered similar issues during their testing. The technology often has difficulty identifying objects or stationary vehicles, and some of the systems actually steered toward hazardous situations instead of away from them according to the report. The IIHS says that it is working to develop a ratings system for autonomous vehicle safety systems and warns drivers to remain engaged and vigilant even when using this type of technology. The nonprofit group has also asked car manufacturers to avoid giving their technology names that may exaggerate its capabilities.

Systems like Tesla’s Autopilot and Volvo’s Pilot Assist constantly gather and store information. This data is sometimes used by police to find out what happened and how motorists acted in the seconds leading up to a car accident, and it could also be used by experienced personal injury attorneys to establish that their clients were harmed due to the negligent behavior of others.