The attack, which was carried out on Sunday night, left eleven of Gothenburg’s toll cameras covered in yellow paint.
“They’ve been shot at with paint, probably from paintball guns,” Eva Rosman, spokeswoman at the Swedish Transport Authority (Transportstyrelsen), told the Göteborgs-Posten (GP) newspaper.
Officials managed to clean four of the cameras immediately, but the other seven remained out of service for the rest of Monday.
The attack is not the first time the cameras have been subjected to vandalism.
“So far it’s been individual stations now and then, but there have been six incidents since the cameras were introduced in January,” Rosman told the paper.
Gothenburg residents upset by the fees have reacted especially to the locations of the cameras in the city, with many erected in residential areas.
The locations also helped explain why the suspected paintballers were able to get such close access to the cameras. In Stockholm, the congestion cameras installed in 2007 are mostly located on large roads and bridges.
The transport agency plans to report the matter to the police.
The system, aimed at financing infrastructure investments, reducing
greenhouse gases, and cutting traffic in the city centre by around 15 percent, includes 40 toll stations around the city.
Motorists entering and leaving the city on weekdays must pay between eight and 18 kronor (between $1 and $3) depending on the time of day, with an upper limit of 60 kronor a day.