Mobile groups are an operative part of direct performance of the control activities of the customs service. Their task is to carry out controls over goods subject to customs or tax supervision and to perform other competences of the customs administration. Through motorized and pedestrian patrols, mobile groups control, e.g., compliance with the conditions of the particular customs procedure into which goods have been released or the conditions stipulated in the permit for operation of a free zone. They also carry out tasks in the area of detection of goods violating some intellectual property rights. The mobile groups also control vehicles on roadways and their freight spaces, personal documents and documents related to the transported goods, including documents proving compliance with the specified route. They control compliance with the obligation to pay fees for the use of certain sections of superhighways and throughways. An important competence of the mobile groups lies in control of the weighing and measuring of trailer truck units. The groups also pay considerable attention to control of the transport of dual-use goods in the framework of the Community. In this area, they cooperate closely with the other state administrative bodies, especially with the Licence Administration of the Ministry of Industry and Trade of the Czech Republic.