[InSteady]

>if you make people feel like they bear all responsibility, it might help marginally even if it isn't legally effective.

Since we are talking about a system that needs a human on alert and ready to take over at any time to function safely, I wholeheartedly agree. Human nature is still human nature, people will zone out and look for diversions regardless, but fear will motivate some to be a bit more vigilant in spite of the boredom of staring intently at a road that you aren't personally navigating.