The senator also wanted Tesla to implement "backup monitoring systems" beyond the steering wheel torque monitor that checks for hands on the wheel. That would keep at least one system checking for driver attentiveness, and might reduce the chances of someone tricking Autopilot into staying active. At present, Autopilot will warn you if your hands are off the wheel for too long, and will force you to drive manually for the rest of the trip if you ignore the warning for long enough.
We've asked Tesla if it can comment on Markey's recommendations. In its earlier response letter, it pointed out steps taken to improve Autopilot's safety. The company added warnings for red lights and stop signs in 2019, and updates to its steering wheel checks theoretically prevent sleepy or drunk drivers from using Autopilot as a crutch. Videos of people abusing Autopilot represented only a "very small percentage" of Tesla's customer base, according to the letter.
Markey's requests aren't binding. They do put further pressure on Tesla to tweak Autopilot, however, and suggest there could be legislation or regulation in the future if misuse remains a problem.