50 km/h and carpooling: How is the Paris ring road doing?

The first assessment is promising two months after the establishment of the carpool lane on the Paris ring road.

Two months after its launch, the dedicated carpool lane on the Paris ring road shows promising results. Established on March 3, 2025, by the City of Paris, this initiative aims to ease traffic and reduce disturbances. The Paris Urbanism Workshop (APUR) has just published its first assessment.

The first lesson: the left lane, now reserved for vehicles carrying multiple passengers, experiences reduced traffic. On average, 184 fewer vehicles travel there each hour, representing a decrease of 3%. This reduction promotes better flow, with an average speed 4 km/h higher than on other lanes. Moreover, since May 2, penalties have been imposed on single drivers improperly using this lane.

Is it really a necessary evil?

However, this measure does not work alone. Since October 2024, the maximum speed across the entire ring road has decreased from 70 to 50 km/h. This new limit has led to a notable reduction in noise disturbances, especially at night, and an improvement in road safety. Between March and April 2025, the number of accidents fell by 14% compared to the same period in 2024.

By combining these two measures, the assessment is even more significant. The congestion rate dropped by 27% between March-April 2024 and the same period in 2025, and overall traffic has slightly declined (-5%). According to APUR, the speed limit alone would have contributed to a 17% decrease in accidents over six months.

With its 1.5 million daily trips, the ring road remains a critical axis. This first assessment encourages the municipality to continue along this path, hoping for lasting effects on traffic, pollution, and safety.

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