Motor traffic appears to be less polluting than anticipated in the past. Over the period 1990–2005, emissions of fine particles and nitrogen oxides were 5 to 15 percent lower than anticipated so far.
More accurate data on the amount of kilometres covered and new views with respect to emissions of air-polluting substances per vehicle-kilometre led to a downward adjustment of estimates on emissions of pollutants by road traffic over the period 1990–2005.
The latest figures on the total distance travelled by motorcars on Dutch roads published by Statistics Netherlands show a reduction by 5 percent relative to earlier estimates. The new emission factors calculated for fine particles and nitrogen oxides prove to be 6 percent below the previous level.
Combustion emission of fine particles by road traffic
Combustion emission of nitrogen oxides by road traffic
The adjustments did not lead to fundamental changes in the overall trend, but emission levels were reduced. Despite the increase in vehicle-kilometres by almost 40 percent, the overall emission level, except for carbon dioxide, was reduced by 50 to 70 percent compared to 1990. The reduction is the result of more rigid European environmental requirements for new motor vehicles.
Emissions produced by road traffic
Road traffic remains one of the principal polluters
Road traffic is one of the principal producers of air polluting substances. In 2005, the share of road traffic in national emissions of fine particles, nitrogen oxides and carbon monoxide was 19, 28 and 48 percent respectively. The share in emission of carbon dioxide, the major contributor to the greenhouse effect, was 16 percent.