we have them here in tucson.put in last year,and they have made the city lots of money.There are some pretty bad drivers here.As Needles said,they do take your picture if you so not stop below the line below the crosswalk(if that makes sense.and then you have to go to class for 8 hrs.at a cost of 250.00,or pay the 322.00 dollar fine.I havent been caught yet,I do my best to avoid the intersections that have them.both my daughters have been caught,new drivers, and its a wake up call for them but they are more cautious