Could the new speed limits increase pollution levels in cities?

Could the new speed limits increase pollution levels in cities? Experts in the field have warned that the new speed limits in urban areas could lead to an increase in pollution levels. As you may have read a few days ago, the new urban speed limits came into force on 11 May.

The Directorate-General for Traffic (DGT) has decided to prohibit driving at more than 20 km/h on roads with a single shared platform for carriageway and pavement. On roads with a single lane per direction of travel, the maximum speed will be 30 km/h, and 50 km/h on roads with two or more lanes per direction of travel, for safety reasons.

The World Health Organization, also known by its acronym WHO, has advised that vehicles should drive more slowly in urban areas, as this would reduce the risk of pedestrian collisions by up to 50%.

Reducing speed may have other consequences in cities

A few days ago we told you that driving at speeds between 20 and 30 km/h can lead to a number of breakdowns, especially in components such as the clutch or the particulate filter. The problem will not only affect your car; the environment could also be considerably harmed.

Experts in the field have agreed that by lowering speed limits, the environment may be affected. Because vehicles cannot exceed 10, 30 or 50 km/h, depending on the road, they must drive, for most of the time, in low gears. This runs counter to the principles of efficient driving, which advocate driving in higher gears for as long as possible. The ideal is to use first gear to “pull away” and shift into second once about six metres have been covered, into third at around 30 km/h, into fourth from 40 km/h and into fifth above 50 km/h.

With the application of the new urban speed limits, it would not be possible to go beyond third gear. Likewise, mechanics have argued that driving at low speed in low gears causes polluting particles to accumulate in the exhaust system, which can lead to wear on the component and an increase in the polluting emissions that reach the atmosphere.