adaptation of the 1958 agreement to technological progress, improved road safety and environmental protection and harmonization of environmental measures – regulations are amended by:…/Rev.X – a revision of the text that includes all the previous texts of the regulation in vigo. …/Amend.X – an amendment to the text of the current regulation or a new set of amendments to the regulation amending the registration mark…./Corr.X – a correction consists of editorial corrections of errors in the published text. Because the corrigendal is called „ab initio,“ the effective date indicates the date of its adoption by the AC.1 management committee. Under the 1958 agreement, a regulation does not provide for different levels of rigour. However, when a regulation is amended and at least one-fifth of the contracting parties applying the unchanged regulation state that they wish to continue to apply the unmodified regulation, the unchanged regulation is considered an alternative to the amended regulation. Thus, it will be formally in the Regulation.In such a case, the contracting parties will be able to choose which alternative they wish to accept. The party opting for an earlier version must accept the authorizations granted under the latest amendments. However, the party opting for the most recent amendment is not required to accept the authorizations granted for earlier versions of the regulation. The Transatlantic Trade and Investment Partnership (TTIP) negotiations examine issues relating to the different standards of the automotive regulatory structure. TTIP negotiators are trying to find ways to reduce regulatory disparities, which could reduce costs and boost additional vehicle trade.  The agreement to establish comprehensive technical rules for wheeled vehicles, equipment and parts that can be mounted and/or used on wheeled vehicles, or the 1998 agreement, is a subsequent agreement.
Following its mission to harmonize vehicle regulations, the EEC-UN resolved the main problems (administrative provisions relating to type reception against self-certification and mutual recognition of receptions) that prevented countries not signatories to the 1958 agreement from participating fully in their activities. At present, it is not possible to design a single model of car that fully complies with the requirements of the United Nations and the United States, but it will be easier to develop the technology and both rules. Given the size of the U.S. auto market and the diversity of marketing strategies in North America, unlike the rest of the world, many manufacturers produce vehicles in four versions: North American, UNECE Right-hand drive (RHD), UNECE Left-hand drive (LHD) and the rest of the world (for unregulated countries or countries with poor fuel quality…. 15] Vehicles sold and put into service in a country must comply with that country`s rules and standards. The registration procedure of this country requires the registration of the vehicle and/or its components. The existence of separate national licensing rules and procedures in different countries requires costly design changes, additional testing and duplicate approvals.