ADR (formally, the European Agreement concerning the International Carriage of Dangerous Goods by Road (ADR) is since 1957 United Nations treaty that governs transnational transport of hazardous materials.
RID is the European agreement for the transport of dangerous goods by railway, and mainly in accordance with the ADR rules and regulations.
The agreement itself is brief and simple, and its most important article is article 2. This article states that with the exception of certain exceptionally dangerous materials, hazardous materials may in general be transported internationally in wheeled vehicles, provided that two sets of conditions be met:
regulates the merchandise involved, notably their packaging and labels.
A trailer is generally an unpowered vehicle towed by a powered vehicle. It is commonly used for the transport of goods and materials.Trailer can be called as a semitrailer in some transportation methods. A semi-trailer is a trailer without a front axle. A large proportion of its weight is supported either by a road tractor or by a detachable front axle assembly known as a dolly. A semi-trailer is normally equipped with legs, called "landing gear", which can be lowered to support it when it is uncoupled. Trailers are availabe as flat, with taupolin or with container-locks. Specially for the transport of Tankcontainer are trailers which ends with a construction to keep possible spillage on connection/disconnection of tubes for loading or unloading. This is a safety for enviroment. Sizes and measures of trailers are ruled clearly on the 128th articles on Road Traffic Regulations.