The 1998 agreement currently includes 38 parties and 20 United Nations that have been created in the Un World Register. The EU became a contracting party to the agreement on 24 March 1998. The 1958 agreement currently has 56 parties and 149 UN regulations attached. Global technical harmonization of vehicles is governed by two international agreements – the 1958 agreement and the 1998 parallel agreement. These agreements create globally harmonized requirements to ensure a high level of safety, environmental protection, energy efficiency and theft protection. Both agreements help remove technical barriers to trade and prevent the creation of new agreements. EU participation gives producers easy access to non-EU markets. The 1958 Agreement on Technical Vehicle Harmonization was established by the United Nations Economic Commission for Europe (UN-EEC). The agreement provides the legal and administrative framework for the establishment of unified international rules with most unified countries, even if they do not formally participate in the 1958 agreement, recognize THE provisions of the United Nations and reflect the content of UN rules in their own national requirements, either authorizing the importation, registration and use of UN-type vehicles of the type GENEIGHMT or both. The two main exceptions are the United States and Canada (excluding lighting requirements); UN regulations are generally not recognized and UN compliant vehicles and equipment are not permitted for importation, sale or use in both regions unless they are considered to be in compliance with regional vehicle safety legislation or restricted non-traffic (e.g. B car show screens).  The first signatories to the 1958 agreement include Italy (28 March), the Netherlands (30 March), Germany (19), France (26), Hungary (30 June), Sweden and Belgium.
Initially, the agreement only allowed the participation of the ECEC member countries, but in 1995 the agreement was revised to allow the participation of non-MEMBERS of the ERC. Current participants include the European Union and its member countries, as well as non-EEC-UN countries such as Norway, Russia, Ukraine, Croatia, Serbia, Belarus, Kazakhstan, Turkey, Azerbaijan and Tunisia, and even remote regions such as South Africa, Australia, New Zealand, Japan, South Korea, Thailand and Malaysia. In recent years, the European Union has decided to replace as many European directives as possible with the 1958 UN regulations and to refer directly to these UN rules in EU legislation. Revision 3 of the 1958 agreement came into force on 14 September 2017. The 2013/454/EU and 2013/456/EU council decisions change the decisions on the two agreements after the Lisbon Treaty comes into force. The 1998 agreement applies in parallel with the 1958 convention. The aim is to further improve the international harmonization process by developing global technical rules (GTR). The main difference is that the parallel agreement does not provide for mutual recognition of authorisations issued on the basis of global technical rules.