The 1958 Agreement of the United Nations Economic Commission for Europe (UN/ECE) on technical harmonisation in automotive design, performance, and construction is celebrating its 50th birthday. The Agreement has resulted in some 126 regulations on issues relating to safety performance and equipment, environmental protection, energy efficiency and theft-resistance of motor vehicles. For example, the ECE agreement on electronic stability control enables manufacturers to develop one ESC system legal for sale in all the world’s markets except North America, which does not subscribe to ECE regulations. In addition to avoiding divergent legislations and duplication of administrative procedures, one single standard at the UN level also contributes to simplifying EU legislation. For example, the CARS 21 Group identified 38 EC directives which could be replaced with international ECE regulations. Global technical harmonisation is a key factor in strengthening the competitiveness of the European automotive industry worldwide.