I can’t speak for Boston, but for the rest of the world, there’s one place this feature could be highly useful–handicapped parking spots where some numbskull (polite term) has parked on the yellow slashed lines painted to give people with disabilities extra room to lower a ramp, or simply to get in and out of their cars. For that matter, it would increase the number of spots available for people with disabilities. My daughter uses a wheelchair, and has the appropriate “handicapped parking tag.” She often has a hard time actually using these spots because some fool has tried to make an extra spot where none exists, or who is “just going to be there a minute,” and parks where they do not have the credentials to park. The ability to back the car out long enough to load her wheelchair into the car when she drives herself would be priceless.
And if you’re the one doing it, stop it!