Sen. Edward Markey, D-Mass., wants Tesla to rebrand and add safeguards to its cars' Autopilot feature.
Markey, a member of the Commerce, Science and Transportation Committee, released his recommendations to the company on Friday after his review of the feature.
"Autopilot is a flawed system, but I believe its dangers can be overcome," he said in a statement. "I have been proud to work with Tesla on advancing cleaner, more sustainable transportation technologies. But these achievements should not come at the expense of safety. That's why I'm calling on Tesla to use its resources and expertise to better protect drivers, passengers, pedestrians and all other users of the road."
Markey said his two recommendations come after media reports that show Tesla drivers abusing the Autopilot system. The first recommendation is a rebranding of the Autopilot feature to clarify that it is not fully autonomous, meaning the driver has to remain in control of the vehicle while Autopilot is turned on. Second, Markey wants Tesla to build more safeguards into the feature that prevents users from working around the system.
Tesla representatives were not immediately available for comment.
Autopilot enables Tesla vehicles to steer, accelerate and brake automatically within their lanes, and move into different lanes. According to Tesla's website, "Current Autopilot features require active driver supervision and do not make the vehicle autonomous."
Markey criticized Tesla's Autopilot feature at a Commerce Committee hearing on self-driving vehicles in November. He demanded then to know what the National Highway Traffic Safety Administration (NHTSA) was doing to compel Tesla to stop Autopilot "cheats," referring to individuals who work around the safety features already in Tesla cars.
"In your inadequate and unconcerned June 2018 response, Tesla failed to recognize the potential harm your Autopilot system could cause," Markey wrote after the hearing to Tesla CEO Elon Musk, referencing an earlier letter he had written expressing concern about the feature.
Tesla's senior director of government relations, Alexandra Veitch, responded in December to Markey's criticism and requests for more information on Autopilot.
"Tesla fully shares your commitment to increase occupant safety and to reduce fatalities on U.S. roads," she wrote in a letter. "We also share your belief in developing active safety features that promote responsible driving habits."
— CNBC's Lora Kolodny contributed to this report.
Correction: Alexandra Veitch is senior director of government relations at Tesla. An earlier version misidentified her.