Transparency of data in the regulation of vehicle emissions in the European Union and United States

Published Tue, 2017.09.05 | By

Défense Terre


Legal brief summarizing public access to vehicle emissions data in the European Union and United States.

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Compliance testing and related activities generate a significant amount of data and information on new and in-use vehicles. By making the data and information freely available to the public, manufacturers, test facilities, and regulatory agencies become more accountable. Data transparency informs citizens and empowers them to complement government efforts in validating vehicles’ compliance with emission and efficiency standards.

Third-party, confirmatory testing is an important source of credibility in the vehicle type approval process. Access to the vehicle testing data needed to conduct confirmatory testing, however, is uneven, and dependent on where the vehicle was type-approved. For example, in the EU, the German type-approval authority KBA publishes a database each year containing relevant testing data for all the vehicles approved in Germany. Other EU Member States do not publish such data.

Manufacturers assert that releasing vehicle emissions data would compromise confidential business information. But available evidence refutes that claim. The US EPA has made measured coastdown parameters from light-duty vehicles publicly available since 1999, with no harm to US manufacturers.

With this in mind, the ICCT commissioned Défense Terre to produce a legal brief summarizing access to vehicle emissions data in the EU and US, detailing what data are available and how.