Drivers using advanced driver assistance systems like Tesla (TSLA.O) Autopilot or General Motors (GM.N) Super Cruise often treat their vehicles as fully self-driving despite warnings, a new study has found.

The Insurance Institute for Highway Safety (IIHS), an industry funded group that prods automakers to make safer vehicles, said on Tuesday a survey found regular users of Super Cruise, Nissan/Infiniti (7201.T) ProPILOT Assist and Tesla Autopilot « said they were more likely to perform non-driving-related activities like eating or texting while using their partial automation systems than while driving unassisted. »

The IIHS study of 600 active users found 53% of Super Cruise, 42% of Autopilot and 12% of ProPILOT Assist owners « said that they were comfortable treating their vehicles as fully self-driving. »

About 40% of users of Autopilot and Super Cruise – two systems with lockout features for failing to pay attention – reported systems had at some point switched off while they were driving and would not reactivate.