Section 29 (3) of the Road Traffic Regulations (StVO) stipulates that traffic with vehicles and trains whose dimensions, axle loads or total masses actually exceed the generally permitted legal limits require a permit. This also applies to traffic with vehicles whose design does not allow the driver a sufficient field of vision. If, on the other hand, the exceeding of the limits only results from the load, an exceptional permit is required in accordance with Section 46 (1) No. 5 of the German Road Traffic Regulations (StVO).
A permit for large-volume and heavy transports (special transports) can only be issued if the vehicle or vehicle combinations in question have a vehicle-related special permit in accordance with Section 70 (1) No. 1 or 2 of the Road Traffic Licensing Regulations (StVZO).
Permits are issued on application and depending on the circumstances of the individual case, for a maximum period of three years, as an individual permit, short-term permit or permanent permit. Permanent permits can be issued for a specific route or for a whole area. They are always subject to revocation.
The basis for the official decision is usually the implementation of a hearing procedure, in which in particular the road authorities located along the planned transport route are heard. The purpose of this is to assess the risks posed by, for example, a particularly wide transport or a particularly heavy transport for other road users or the road infrastructure (especially bridges) and, if necessary, to counter these risks by imposing official requirements and conditions.
If the safety or order of traffic or the protection of the road infrastructure so requires, the permits are subject to requirements and conditions. For example, time restrictions may be imposed (e.g. transport during the night when there is little traffic) or the applicant may be required to provide security for the transport by providing private escort vehicles (e.g. of the BF-4 type).
The escort of special transports by the police is to be provided by the permitting authorities only in cases where securing the transport by private transport escorts is not considered sufficient.