When it comes to emissions from road users, there are four main exhaust ingredients that have negative effects on health and the environment: nitrogen oxides, particulates, hydrocarbons and carbon monoxide. Emissions of these substances are strictly regulated in most countries and the limits for what each vehicle may emit are being constantly lowered.
A lot has been done
Within the EU, road traffic emissions of nitrogen oxides have dropped by over 30 percent during the past decade, although transport itself has increased by 20 percent during the same period. This has brought about a significant improvement in air quality in many cities and suburbs. A similar development can be seen in countries such as the US and Japan. Many countries in other parts of the world are closely following either European or American legislation.
For heavy diesel vehicles, the main focus is on nitrogen oxides and particulates. Emissions of these substances from new trucks are almost 100 times less than 20 years ago.