I've seen loads of "out of towners" making a big pig's ear of driving around the tram-only places. Usually the biggest punishment they have to endure is the nearest tram driver leaning on his bell as if his life depended on it and every pedestrian within a 100 metre radius turning to do the obligatory stare with an approximate 5%* break-away group slowly tapping their forehead with a forefinger whilst shaking their heads.

In the absence of an immediate police presence the local "staring/tapping/head-shaking constabulary" take care of minor traffic infractions.

*the percentage of forehead tappers increases proportionately with the stupidity of the infraction.