Road transport is an important source of both greenhouse gases and air pollutants.
Despite improvements in vehicle efficiencies over past decades, today the sector is responsible for almost one fifth of Europe's greenhouse gas emissions. Emissions from vehicles also lead to high concentrations of air pollutants above EU standards in many of Europe's cities. This report provides a summary of the current knowledge on vehicle emissions in Europe. It also explains how emissions are monitored and the common technologies used to limit them.