Reducing speed in the city, an ecological argument? Not for the town hall of Paris, which especially emphasizes the safety of pedestrians and the reduction of noise in the capital when the measure is applied on August 30. However, the question arises.
Indeed, in an interview with JDD this August 29, David Belliard, Parisian deputy in charge of mobility, roads and the transformation of public space (Europe Ecology – The Greens), ensures that the measure should make traffic more fluid. However, traffic jams cause decelerations and accelerations. These are the most “dangerous, noisy and polluting” moment, according to him.
But not all are necessarily of this opinion. Asked by France Blue, the general manager of the association Respire, Tony Renucci, explained that below 50 km / h, the heat engines are no longer optimized. Therefore, “the slower you drive the more pollution”. According to several studies, this statement is correct when it comes to average speed, without taking into account the phases of acceleration and deceleration.
Scientifically, it is difficult to predict the exact impact of this measurement on air quality. And it is certainly for this reason that the town hall of Paris does not focus its communication on this subject. Indeed, the Environment and Energy Management Agency (ADEME) had compiled several international studies on the issue in 2014. However, in urban areas, no real conclusions could be drawn.
“Unlike fast axes, no trend in concentrations or emissions seems to emerge. The results of studies carried out on urban development show significant variations depending on the scenarios chosen or the typologies of zones ”, we can read in the report. Faced with dubious scientists, it will therefore be necessary to wait for the medium term to know whether the measure will have a beneficial impact or not on pollution in the French capital.