Member States of the EEC. To avoid this and to protect the common market, all Member States adopt the same requirements, either in addition to or in place of their existing rules, in order, in particular, to allow the EEC type-approval procedure, defined by Council Directive in 1970. 1970s In 1 August 1970, United Nations Regulation No. 15. is registered by the UN-ECE, for vehicles equipped with a positive-ignition engine or with a compression-ignition engine with regard to the emission of gaseous pollutants by the engine - method of measuring the power of positive-ignition engines - method of measuring the fuel consumption of vehicles. This UN-ECE regulation number 15 had three kind of tests performed with octane 99: Operating cycle used for TYPE-I TEST, up to 50 km/h speed at third gear and up to 1.04 meter per square second acceletation TYPE-II TEST: Carbon-monoxide emission test at idling speed TYPE-III TEST: Verifying emissions of crank-case gases In 1978, an Energy Tax Act mandated new testing in order to determine the rate of the guzzler tax that applies for the sales of new cars. This testing, the EPA Federal Test Procedure, commonly known as FTP-75 for the city driving cycle, are a series of tests defined by the US Environmental Protection Agency (EPA) to measure tailpipe emissions and fuel economy of passenger cars (excluding light trucks and heavy-duty vehicles). In 1983, in the European Union, directive 83/351/EEC amended directive 70/220/EEC against air pollution by gases from positive-ignition engines of motor vehicles, in conformity with ECE Regulation No. 15/04. 1980s, NEDC In the 1980s, the old NEDC as European homologation lab-bench procedure was established to simulate urban driving condition of a passenger car. In 1988, in the EEC, Directive 88/76/EEC, change law to rules more stringent than ECE Regulation 15/04. 1990s In 1992 the NEDC was updated to include also a non-urban path (characterized by medium to high speeds). In 1997 the CO2 emission figure have been added, too. The structure of the NEDC is characterized by an average speed of 34 km/h, the accelerations are smooth, stops are few and prolonged and top speed is 120 km/h. In 1996, in the USA, the EPA revised the vehicle certification test, to introduce new driving conditions including aggressive driving behavior, high acceleration rates or air conditioners' operation: The new test introduces: speeds of 80 mph (129 km/h) instead of 57 mph (92 km/h).