Oh I misunderstood your original comment. What incentive do the towns/vendors have to setup these systems in that case?

The incentive is to make their streets safer. If they don't think the systems do that, then clearly they shouldn't be setting up the systems?

I don't know if you've noticed but governments rarely do the right thing for the sake of it.

The towns can still pay vendors, just as they pay vendors for lots of things. They just can't keep any of the ticket revenue generated.

The vendors can now just tip the town officials for choosing them.