Vehicles (swap bodies or semi-trailers) must be approved by the proper authorities for the Road-Railway Combination service. 

Code plates must be applied on load units for vehicles approved for Road-Railway Combined Transport.

The railway profile's technical data is indicated on the code plate certifying the vehicle's compatibility with the transportation line. Compatibility of the load units (swap bodies or semitrailers and wagon) profile with the railway network is valuated using maps indicating the railway lines' maximum code values.