I'm not sure if it'll help people avoid accidents.

On the one hand, you might get a few people who would be handling their phone to keep their eyes on the road more.

On the other hand, it might facilitate phone use in a way that people might use their phone now when they wouldn't have before (because handling it felt too distracting but this doesn't). I think this is a tangible risk.

There have been papers published that point out that hands free use isn't anywhere near safe.

Side note: not sure why the downvotes or what the other somewhat strident replies are about. I don't quite agree with you but it's not downvote worthy.