New on-road car emissions testing comes into force in the European Union on Friday as regulators strive to prevent a repeat of Volkswagen’s diesel emissions scandal. The German carmaker’s admission in September 2015 that it used software to cheat U.S. diesel emission tests highlighted the laxness of the EU’s own tests, prompting reforms.

The new process, known as Real Driving Emissions (RDE), is designed to reflect everyday driving conditions and to narrow the disparity between road and laboratory test results, according to Reuters.

Until now only laboratory tests have been used as the benchmark for assessing vehicle emissions, with carmakers employing a variety of strategies – such as taping up doors and windows – to produce better results than possible on the road.

European Commission research shows inadequate testing has led to on-road emissions of toxic nitrogen oxides as high as 15 times the regulatory limit.

“For the time being, diesel cars remain part of our lives and we must rebuild confidence in this technology,” EU Industry Commissioner Elzbieta Bienkowska said in a statement on Thursday. “That is why having new and more reliable tests for new cars is essential.”

The new rules will apply for all new car models by September 2017 and will be phase in for all new vehicles by between September 2018 and 2019.