It's worth noting that Subaru vehicles have been doing vision-only adaptive cruise / lane keeping / emergency braking for many years, which they brand Eyesight. In my personal experience its adaptive cruise is as good or better than most other cars I've driven which use radar.

(Admittedly the reasons why the Subaru impressed me was more for its programming rather than absolute precision. I liked how smoothly it transitioned between following and open road ahead. Much less jerky.)