Generally speaking, the Germans are a serious group of people and live by the rules, except perhaps trying to avoid paying tax. It is said that in Germany there is a regulation for everything. If it’s not regulated, it’s not aloud. There are also almost as many exceptions to the rule. Many professions exist simply for that reason.
The size of fines and penalties in the Ruhr Metropolis are surprisingly low compared to most other European countries, They seem to reflect a so-called collective responsibility, Vernunft. It is simply assumed that most residents should be and are honest. There are though, numerous opportunities to benefit the public purse.
Driving is one example. It’s true, there is no general speed limit on German motorways, Autobahnen, but many stretches are regulated by signed speed limits, which are often closely policed with unmarked cars and cameras. Inner city radars are widespread as are spot checks with handheld gadgets.
Speeding and other traffic offences are often subject to on-the-spot fines. Pedestrians can be called to account for jaywalking, crossing red lights or throwing garbage on the streets. Cyclists can also be called to order quite easily for breaking the law. Especially if they give an impression of being inebriated.