Speed limits can reduce air pollution

Levels of air pollution can be significantly reduced in urban areas by introducing traffic speed limits, according to a new study. Air quality was studied along a section of the Amsterdam ring road, where the speed limit was lowered from 100 to 80 km/h. It was found that particulate matter (PM) was significantly reduced, by up to 15 per cent, during the period of the speed restriction, although no significant effect on nitrogen oxides was observed. The study also found that congestion levels did not increase, contrary to concerns expressed before the restriction was put in place. The study claims to be the first to clearly demonstrate that reduced speed limits can improve air quality.

Source: Science for Environment Policy, DG ENV, 29 January 2009

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