This presentation reviews the consideration of cross matrix modules to enable GRBP and subgroups to evaluate regulation amendment proposals regarding their impact on real world traffic. The cross matrix addresses how vehicle sound emission regulations influence sound levels considered by road traffic noise models. Four existing sound source models are compared: EU CNOSSOS, SonRoad18, CNOSSOS JP, and HMG ASJ RTN. HMG sound power models derived from pass-by data on ISO 10844 compliant test tracks evaluate EVs and include type approval data for ASEP and RD-ASEP. Statistical pass-by simulations using randomized vehicle selection enable calculation of LA, eq for traffic scenarios with varying fleet compositions. To advance this work, sound power models for missing UN R51.03 and UN R41 vehicle categories, especially buses and trucks and new propulsion technologies, must be created and reference scenarios established and agreed upon.

The Task Force Data Analysis held 14 meetings, with 12 used to eliminate database errors and 2 to begin data analysis. The analysis revealed the need to better understand the concept and history of RD-ASEP development. Questions were raised regarding whether RD-ASEP should follow envelope functions framing typical sound behaviour of vehicle components or average behaviour with acceptable tolerance. Comparing databases from 2017/2020 and 2023/2024 showed different pass/fail rates across vehicle types. The group seeks clarification on RD-ASEP model optimization, accuracy expectations, and documentation explaining historical background and parameter selection.