Submergence test procedure: During vehicle submergence, at least 1 window per row of seats shall be capable of being fully opened after the vehicle enters the water up to 2 minutes. The container shall accommodate the vehicle with sufficient dimensions to allow it to remain in water for 2 minutes without contacting walls or floor, or alternatively open-water test sites may be used provided they comply with test conditions; freshwater lakes, reservoirs, and saltwater bodies are not permitted. The vehicle’s master control switch shall allow window operation; the vehicle mass shall be unladen kerb mass. The vehicle shall be lowered into water at a horizontal angle of 0–10 degrees. Time zero is when lowering straps become slack and the vehicle starts floating freely. The vehicle shall remain in water for 2 minutes from T0 and shall not contact the container floor until fully submerged. After 2 minutes, the window shall be capable of being fully opened using a remote system, or for vehicles equipped with automatic window lowering systems, windows shall automatically lower within 2 minutes. Alternative subsystem tests demonstrating window opening functionality under submerged conditions are acceptable in agreement with the approval authority and the designated technical service.
This document requests sound model documentation through a series of questions. Two models are documented: sonROAD18, last updated October 2024, uses more than 10 vehicle classes and describes sound power levels using propulsion noise and rolling noise components with spectral model coefficients, vehicle speed, road gradient corrections, pavement corrections, and air temperature corrections. The reference pavement is ACMR8 with porosity less than 8%. NExUS, last updated 2025, uses two vehicle classes comparing battery electric vehicles and internal combustion engine passenger cars, describing sound power levels using spectral model coefficients, speed, and acceleration parameters. The reference pavement is dense asphalt concrete AC 11 S. Both models use omnidirectional directivity and position sources 0.05 m above road surface.
sonROAD18 is a Swiss road traffic noise emission model based on CNOSSOS-EU formalism, covering more than 10 vehicle categories with speed ranges 20–130 km/h, calibrated using over 700,000 pass-bys from 2015–2017. NExUS is a research model for noise from battery electric and internal combustion engine passenger cars during acceleration in urban scenarios, based on more than 3,000 real drive trajectories recorded in 2024, with speed ranges 0–60 km/h. Both models predict noise emissions via propulsion and rolling noise components using three octave bands.
An improvement intended to increase vehicle robustness in Annex 3 creates more difficulties in RD-ASEP assessment. Small variations in Annex 3 parameters may result in unexpected substantial exceedances in Annex 7. Minimal changes in the calculated tyre share at the anchor point may cause vehicles to fail Annex 7. The regulation should ensure realistic test effort and workload for compliance verification, as current requirements may require up to 180 combinations per type across test tracks, temperatures, driving modes, and tyres.
Working draft informal document for presentation to the 82nd (January 2021) GRPE session.