The systems that allow drivers to take their hands off the wheel are convenient but don’t improve safety because people are often too reliant on them and end up paying more attention to their cellphones and infotainment screens than to the road, the head of the National Transportation Safety Board said Tuesday.

At Tuesday’s hearing on two fatal crashes involving Ford’s Blue Cruise system, the NTSB recommended that Ford find ways to improve the way its system monitors drivers, and urged the federal government to establish minimum safety standards. Even though this investigation focused on these Ford crashes, the board made clear that their concerns apply across the industry.

“These systems function primarily as convenience features rather than safety enhancements,” NTSB Chairwoman Jennifer Homendy said.

The 2024 crashes in Texas and Pennsylvania killed three people when Ford Mustang Mach-E SUVs slammed into stopped vehicles. In both cases, the drivers were distracted in ways the system failed to recognize. The Texas driver only briefly glanced at the road while searching for a charging station, and the Pennsylvania driver appeared focused on the cellphone she was holding on top of the steering wheel in front of her.

Homendy said automakers are marketing these systems as safety improvements that allow drivers to take their hands off the wheel and focus elsewhere. To illustrate her point, she showed a Ford commercial that depicted a mother in a driver’s seat pretending to conduct a symphony with her eyes closed while talking to kids in the backseat.

Philip Koopman, professor emeritus at Carnegie Mellon University and expert on self-driving vehicle safety, said the NTSB findings highlight longstanding concerns about the limitations of these driver assistance systems and the fact that more advancements are needed.

“These concerns continue to be a problem,” Koopman said. “The finding today is that the journey is not over. More work is needed.”

Ford said in a statement that it remains committed to safety and “we will take the NTSB’s recommendations under serious consideration as we continue to evolve our driver-assist technologies and encourage responsible road behavior.”

Cathy Chase, president of Advocates for Highway and Auto Safety, said that drivers who are already addicted to their cellphones think it’s OK to check them while using these systems because they trust them.

“Our brains are just wired in that if we think that a system is going to take over and reliably handle a driving task, we get bored and we look for something else to do,” Chase said.

There are currently no clear U.S. government safety standards for the systems, so each automaker’s version of this technology can vary greatly, said Michael Graham, NTSB vice chair.

The NTSB has previously investigated a number crashes involving similar systems, including Tesla’s Autopilot system. Homendy said that it’s not fair to think Tesla’s system is worse because they have reported a large number of crashes. She said Tesla is just much better at reporting crashes. The NTSB recommended that the National Highway Traffic Safety Administration should require automakers to track and report crashes more reliably.

Ford’s Blue Cruise system allows drivers to take their hands off the steering wheel while it handles steering, braking and acceleration on highways. The company says the system isn’t fully autonomous and that it monitors drivers to make sure they pay attention to the road. The systems offered by other carmakers are similar and most of the concerns the NTSB raised apply to all of them.