​​​​​​It's actually very useful in an urban setting because it shows you gaps in traffic. If you need to move into the lane to get around anything or turn left, you have a pretty good idea when to go without looking behind you. Obviously look before you move, but urban riding needs more attention in front of you because a kid or pet is liable to run out into the road at any time.

Also the pavement on the side of the road tends to have a lot of cracks, the travel lanes are usually smoother. Slow residential streets don't get much traffic and the radar lets you just ride in the lane as a matter of course, moving over only when a car comes up behind you.