ABSTRACT
The EC has legislated extensively in this area both to uphold the operation of the single market and to address air pollution from vehicle traffic. The first development was the Directive on Air Pollution from Motor Vehicles 70/220 (for later Directives and their implementing regulations, see p 193, below). As amended and supplemented it sets emission limits for gaseous pollutants (carbon monoxide, hydrocarbons and nitrogen oxides) for petrol and diesel engined motor vehicles up to 3.5 tonnes, that is, cars and light vehicles. Neither this Directive nor subsequent directives controlling emissions impose any obligation upon Member States to ensure that vehicles within their territories comply with directive standards. Rather, it requires Member States not to impose any stricter standards than those contained in the Directive upon vehicles being imported from another part of the EC, a technique referred to as optional harmonisation. This ensures the free movement of goods whilst encouraging car manufacturers to comply with EC standards.
