The men – aged 24 and 25 – would place slabs of cement, pieces of wood with nails in them or heavy chunks of brick onto the road at night, prosecutors allege. Sometimes they would place the objects on the road in the northern city, on other occasions they would place them on entry roads to the Autobahn, the Hannoversche Allgemeine reports.

Police became so concerned by the repeated incidents at one entry road to the Autobahn that they took the measure of reducing the speed limit on it after dark.

On one occasion the men placed a 30 kilogramme cement holder for a road sign on its edge directly in the middle of the road.

Prosecutors say that the crimes took place between 2015 and 2017. The most serious consequence of the reckless crimes was causing a young woman to lose control of her car and crash. Other incidents led to damage to cars.

Investigators were able to arrest the men after they found the DNA of one of them one a plank of wood with nails sticking out of it. Officers arrested the men near the place where the wood was found and were able to match the DNA sample.

A search of their homes found a shelf system from which the offending piece of wood had been cut.

The men have admitted to the crimes, saying they acted out of boredom, frustration and due to stress in their private lives.