First effects of Paris ring road at 50 km/h
The speed reduction to 50 km/h on the Paris ring road is already showing positive effects. Less traffic, pollution, and noise are observed according to initial estimates. This measure aims to improve air quality and safety in the city.
The Paris ring road, an iconic artery of the French capital, saw its speed limit lowered to 50 km/h in July 2024. This decision, part of a broader plan to green the city, is already bearing fruit according to the first analyses published on October 1, 2025, by Le Monde.
Estimates show that traffic volume has decreased by about 10% since the measure took effect. This reduction is due to a deterrent effect on drivers, who are choosing alternative routes or public transport. "This is an encouraging first step toward more sustainable mobility," said an environmental expert interviewed by the newspaper.
Regarding pollution, levels of fine particles (PM10 and PM2.5) have dropped by 5 to 15%, while nitrogen oxide (NOx) emissions have decreased by 8%. These improvements are attributable to a more moderate speed, which reduces intense accelerations and braking. Residents, often exposed to this pollution, benefit directly, especially in adjacent neighborhoods like those in northern Paris.
Noise has also been positively affected: a reduction of 2 to 3 decibels has been measured, representing a notable improvement in acoustic comfort for inhabitants. The ring road, with its 35 km length, typically generates noise above 70 dB, and this decrease could reduce sleep disturbances and health risks.
These effects are temporary and based on preliminary data collected over the first two months. Parisian authorities, in collaboration with Airparif and the Regional Health Agency, are continuing monitoring to assess long-term impacts. While some drivers complain about longer travel times, the environmental benefits outweigh them according to observers. This initiative fits into Paris's commitment to carbon neutrality by 2050.