In what circumstances must you conduct an additional technical check-up of a four-wheeled motor vehicle having a curb weight of 500 kg?

According to the regulations, a vehicle (such as the quad bike seen in the photo) is subject to an additional technical inspection if it has been directed to it by a road traffic control authority. This usually occurs in case of a reasonable suspicion that the technical condition of the vehicle poses a threat to safety or violates environmental protection requirements. This follows directly from Art. 81 para. 11 pt. 1 of the Road Traffic Act.