Traffic road noise and transportation energy efficiency

Future noise emission limits for passenger car are going to lower levels by 2024 (Third phase of R51-03, with a limit of 68dBA for the pass by noise) while social cost of noise for France in 2021, shows clearly that the dominant source of noise pollution is indeed road traffic (81 Bn€ for a total of 146 Bn€).
This R51 regulation is meant to lower the noise pollution from road traffic, however when looking closer to the sound source and their contributions, in particular the tire/road noise interaction, the environmental efficiency of this regulation is questionable.
Indeed: Tire/Road interaction involves tires characteristics, that are constrained by an array of specification for energy efficiency, safety (wet grip, braking, etc…) and it has been proven that there is a physical limit to what could be expected from the tire as far as tire/road interaction noise is concerned.
Road surface, however, shows very wide acoustic characteristics spread with over 15dBA from the quietest to the loudest asphalt, to be compared to 2dBA steps in the regulation and an environmental impact that will depend on the rolling stock renewal rate.
Several cases study in the environment have showed that the best cost/benefit ratio when considering the social cost of noise is to work on the road surface (around 1:20: 1 € spent on the road causes 20€ lowering of the social cost of noise) with an almost immediate implementation.
The real difficulty is that road surface acoustic properties are generally unknown. This paper will present a new patented method from Renault enabling to assess road acoustic data mapping from a simple drive of a Megane E-Tech, quickly and efficiently, with a case study of one territory, issuing the first ever noise pollution control maps, enabling authorities to prioritize roadworks with regard to the most influential parameter on noise pollution, and noise observatory to refine their models.