Tesla’s latest automated lane change update to its controversial “Autopilot” software doesn’t appear to react to brake lights or turn signals, according to a report published Wednesday by Consumer Reports. The update gives drivers the ability to let the car change lanes for them, without any human input.

The company says the update is part of its effort to make driving “more seamless.” But according to Consumer Reports, the technology comes with potentially dangerous ramifications. 

“In practice, we found that Navigate on Autopilot lagged far behind a human driver’s skill set: The feature cut off cars without leaving enough space and even passed other cars in ways that violate state laws, according to several law enforcement representatives CR interviewed for this report,” the report said. “As a result, the driver often had to prevent the system from making poor decisions.”

Tesla faces renewed questions over the safety of Autopilot after federal investigators confirmed the software was turned on during the most recent known fatal crash involving the company’s cars. A Tesla spokesperson appeared to undercut the actual capability of the technology, telling Consumer Reports “it is the driver’s responsibility to remain in control of the car at all times, including safely executing lane changes.”