The European Agreement concerning the International Carriage of Dangerous Goods by Road (ADR) was done at Geneva on 30 September 1957 under the auspices of the United Nations Economic Commission for Europe, and it entered into force on 29 January 1968. The Agreement itself was amended by the Protocol amending article 14 (3) done at New York on 21 August 1975, which entered into force on 19 April 1985.

The Agreement itself is short and simple. The key article is the second, which say that apart from some excessively dangerous goods, other dangerous goods may be carried internationally in road vehicles subject to compliance with:

• the conditions laid down in Annex A for the goods in question, in particular as regards their packaging and labelling; and
• the conditions laid down in Annex B, in particular as regards the construction, equipment and operation of the vehicle carrying the goods in question.

Annexes A and B have been regularly amended and updated since the entry into force of ADR. Consequently to the amendments that entered into force on 1 January 2019, a revised consolidated version has been published as document ECE/TRANS/275, Vol. I and II ("ADR 2019").

The structure is consistent with that of the United Nations Recommendations on the Transport of Dangerous Goods, Model Regulations, the International Maritime Dangerous Goods Code (of the International Maritime Organization), the Technical Instructions for the Safe Transport of Dangerous Goods by Air (of the International Civil Aviation Organization) and the Regulations concerning the International Carriage of Dangerous Goods by Rail (of the Intergovernmental Organisation for International Carriage by Rail). The lay-out is as follows:
 
Annex A: General provisions and provisions concerning dangerous articles and substances
Part 1: General provisions
Part 2: Classification
Part 3: Dangerous goods list, special provisions and exemptions related to limited and excepted quantities
Part 4: Packing and tank provisions
Part 5: Consignment procedures
Part 6: Requirements for the construction and testing of packagings, intermediate bulk containers (IBCs), large packagings, tanks and bulk containers
Part 7: Provisions concerning the conditions of carriage, loading, unloading and handling
Annex B: Provisions concerning transport equipment and transport operations
Part 8: Requirements for vehicle crews, equipment, operation and documentation
Part 9: Requirements concerning the construction and approval of vehicles