"It’s an exception," confirms basketball spokesperson Michael Mager when asked. The club has had an agreement with the city since the hall on the Hardtberg was opened in 2008 for the second play-off final game of the Telekom Baskets Bonn against Alba Berlin. Because of the crowds, cars can be parked on the street Auf dem Kirchbüchel from 7 p.m. to 10 p.m. with appropriate signage.

But: "At this match, the responsible security people didn’t put up any traffic beacons," says Mager. "It was an oversight. They’d forgotten." When the Basketball Bundesliga starts again in October, the parking signs should be put up properly again for the total of 17 home games, just like the additional no-parking signs in the surrounding residential areas.

Does the public order authority know about this regulation for Baskets home games? The press office explains: "Years ago, there were exceptional permits to set up parking spaces on one lane of Auf dem Kirchbüchel during home games. The road was turned into a one-way street during this time." The last of these permits was for 2011, he said. "Since then, there has been no demand." But the club had blocked off the road for the past ten years.

So the question remains why the public order office happened to check on exactly the day when there were no traffic beacons. According to the press office, checks are carried out regularly and everywhere. "Even during home matches, because there are always complaints about parking violations in the surrounding streets," says spokesperson Markus Schmitz. "This is a routine operation." In the vicinity of events, he said, attention has to be paid to whether traffic rules on road safety are being observed.

Joachim Kamlot feels he has been unjustly fined, even though he did not pay attention to whether there were parking signs on Kirchbüchel on 30 May. He expects that the city will cancel his parking ticket. And he says: "Apart from this exception, I don't park my car on a cycle lane unless it’s expressly allowed."

Werner Böttcher knows all about the problem of cars parking on bike lanes. He is involved in the Allgemeiner Deutscher Fahrrad-Club (ADFC) and says: "Hardtberg is not a hotspot for parking on cycle paths." Especially since there are only a few residential areas nearby. The street Auf dem Kirchbüchel is not a place where cycle paths are frequently used for parking - apart from the games of the Baskets.

Then Böttcher does think of two places: at the corner of Kirchbüchel/Provinzialstraße and on Julius-Leber-Straße, where there are glass and paper containers. "People often stop there on the hard shoulder when they put something in the containers," says Böttcher. "There are parking spaces nearby, but then you would have to walk a few metres."

Böttcher refers to his ADFC colleague Ralph Bierett, who keeps an eye on the whole city. He has noticed a few streets where the situation is critical: Rheingasse, Maarstraße and Pützchens Chaussee. You only have to stand there for an hour, and you will see ten people parking on the cycle path.

The city cannot help with the question of how many offences there are per year. The press office says that parking on cycle paths and footpaths is recorded as one offence, so there are no separate statistics. According to the Bonn police, "the city is actually responsible for parked cars.” Nevertheless, patrols do intervene if they observed people parking on the cycle path. According to a police spokesperson, the number of tickets issued by officers for parking on cycle paths was in the low three-digit range last year.

Some cyclists in Bonn use a platform on the net or the city's website to report parking violations. According to Bierett, this alone accounts for 1000 reports. Why does he think that motorists do not obey the rules? "The main reason is convenience," says Bierett. There are usually parking spaces nearby, he says, but that means you have to walk. "There is also a common attitude among motorists: Cars, trucks and buses are road users, but pedestrians and cyclists are not," he says.

Jana Kühl, Germany’s first professor of cycling management at the Ostfalia University of Applied Sciences in Salzgitter, agrees: "But I have hope that it is only a minority that thinks: the road belongs to me." There is a certain "we've always done it that way" mentality. People often say: "I have to park somewhere" or "There are no parking spaces". Over the years, violations of the rules have been dealt with only sporadically. Kühl says: "In order to make people aware that it is not OK to park on the cycle path, violations must be punished consistently."

One problem lies with the wording of the so-called "traffic turnaround" (getting people to use their cars less), Kühl believes. She says it sounds as if car drivers are having something taken away from them, that they are being forced to cut back. But the fact is that it’s very stressful for everyone at peak times when there’s traffic gridlock. "If there’s a shift to cycling and the roads are emptier, it’s much better for everyone, including those who really cannot manage without a car."