| UN R41 Motorcycle Noise | Motorcycle Noise | Uniform Provisions Concerning the Approval of Motor Cycles with regard to Noise The proposal for the 04 series of amendments, adopted at the June 2011 Forum session, will be posted as Revision 2 to the regulation pursuant to the completion of administrative formalities. Motorcycle Noise Motorcycle Noise UN Regulation No. 41 UN R41 | UNR | 41 | |
| UN R51 Vehicle Noise | Vehicle Noise Emissions | Uniform Provisions Concerning the Approval of Motor Vehicles having at least Four Wheels with regard to their Noise Emissions Vehicle Noise Vehicle Noise Emissions UN Regulation No. 51 UN R51 | UNR | 51 | |
| UN R63 Moped Noise | Two-wheeled Moped Noise | Uniform Provisions Concerning the Approval of Two-wheeled Mopeds with regard to Noise Moped Noise Two-wheeled Moped Noise UN Regulation No. 63 UN R63 | UNR | 63 | |
| UN R117 Tire Noise, Wet Adhesion, and Rolling Resistance | Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance | Uniform provisions concerning the approval of tyres with regard to rolling sound emissions and/or to adhesion on wet surfaces and/or to rolling resistance Tire Noise, Wet Adhesion, and Rolling Resistance Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance UN Regulation No. 117 UN R117 | UNR | 117 | |
| UN R138 Quiet Road Transport Vehicles | Quiet Road Transport Vehicles | Uniform provisions concerning the approval of Quiet Road Transport Vehicles with regard to their reduced audibility (QRTV) This Regulation requires an "audible vehicle alerting system" (AVAS) to reduce the risk of collisions with vulnerable road users unable to aurally detect the presence of electrified vehicles. Quiet Road Transport Vehicles Quiet Road Transport Vehicles UN Regulation No. 138 UN R138 | UNR | 138 |