Socio-economic analyses have been made by several different authorities and independent institutions in Denmark and abroad. They underline that it is cost-efficient to require closed particulate filters and city-SCR systems on diesel vehicles in cities since the costs of the air pollution (in the form of illnesses and deaths) are much greater than the prevention and removal costs. As a whole, society could in fact earn money by reducing traffic-related air pollution. Less air pollution in cities will provide more people with a longer and better quality of life. Furthermore, requiring particulate filters and city-SCR systems is in full accordance with the polluter pays the price principle. However, politicians in member states (Denmark included) still hesitate to implement low emission zones requiring technical solutions for both heavy and light vehicles. This is often caused by a misguided protection of business vehicle owners. But as mentioned above, the business vehicle owners can pass on the extra costs directly to the next level in the supply chain and low emission zones will not result in extra costs