Road traffic: volume trends and environmental pressure, 1990-2012

Carbon dioxide emissions

Between 1990 and 2012, carbon dioxide (CO₂) emissions from road traffic increased more or less in proportion to the number of vehicle kilometres.

Nitrogen oxide and particulate matter emissions

Emissions of nitrogen oxides (NO_x) and particulate matter from road traffic decreased year on year after 1990, despite the fact that the number of vehicle kilometres increased by 37% between 1990 and 2012. In the case of NO_x, this can be mainly attributed to the introduction of the three-way catalytic converter in cars and vans at the end of the 1980s in response to emission standards. The reduction in particulate matter (PM₁₀) emissions was mainly due to improvements made in engines. A further reduction, in particular after 2005, was achieved by the use of diesel particulate filters. Almost every new diesel vehicle was supplied with an in-built diesel particulate filter in 2011, and existing vehicles were also equipped with diesel particulate filters (retrofit). By the end of 2012, over 80,000 cars and vans and almost 27,000 heavy goods vehicles had been fitted with a retrofit filter.

Noise nuisance

The decline in noise nuisance from road traffic between 1990 and 1997 came to an end several years ago. The decrease in the early 1990s was the result of noise regulations being applied to new vehicles, the construction of sound barriers and the use of noise-reducing tarmac (ZOAB). The increase since 1997 is a consequence of increasing road traffic intensity.

Policy objectives

The general policy objective is to achieve a decrease in emissions across the economy in addition to growth in gross domestic product (GDP). As far as traffic (road traffic plus other traffic) is concerned, the following objectives were drawn up in the Dutch Fourth National Environmental Policy Plan (VROM, 2001):

• Nitrogen oxide emissions from traffic and transport must be reduced to 158 million kg in 2010 (emissions totalled 164 million kg in 2010, 106 million kg of which were from road traffic). The objective was therefore not achieved.
• Three objectives were set for noise pollution from all sources (industry, road, rail and air traffic), that together should achieve a good acoustic quality in 2030. One of these objectives is that the threshold of 70 dB(A) for homes must no longer be exceeded in 2010. A noise level of 45dB(A) is considered very good, and 65 dB(A) very poor (I en M, 2012).