Vehicles subject to the insurance obligation can only travel if they are in perfect working order and meet the requirements. They are subject to an annual inspection of their mechanical condition with regard to passenger vehicles. This verification is carried out by the services of the Ministry of Public Works or, if necessary, by a professional approved by the said services. If the condition of the vehicle is satisfactory, the owner is issued a certificate attesting to it, free of charge. Otherwise, the vehicle must be represented within the maximum period of one month. If it is not then possible to issue the certificate provided for in the third paragraph, the vehicle is impounded at the owner's expense.