Here's a an article referencing a UK white paper that talks about the issues with level 2 and 3 autonomous vehicles.
https://www.tu-auto.com/adas-level-2-3-avs-are-hazards-experts-warn/
*“With adaptive cruise control (ACC) for instance, it takes twice the amount of time to respond to a sudden braking event than it does when you are manually driving. Drivers may believe that ACC is safer but actually taking your foot off the accelerator pedal and letting the car make the decisions leads to lower workload and can mean drivers are unprepared for an unexpected event.”
University of Sussex object recognition researcher Dr Graham Hole was also questioned for the study and dubs Levels 2 and 3 “the worst of all worlds”. He says: “Human beings are rubbish at being vigilant – vigilance declines after about 20 minutes. With semi-autonomous you are reducing the driver to monitoring the system on the off-chance something goes wrong. Most of the time nothing goes wrong, leading the driver to have massive faith in the system in all conditions, which of course isn’t always the case.”*