At European Community level, noise emissions from motor vehicles have been regulated since the 1970's. The first EEC Directive on permissible sound levels, Directive 70/157/EEC, specified a drive-by noise test and a stationary noise test, with maximum permissible limits being applied to the drive-by noise test result. Since its original publication, the sound level limits specified by this Directive have been reduced a number of times, most recently by EC Directive 92/97/EC. However, European Governments became concerned when the most recent reductions in the permissible sound level limits did not translate into reduced levels of urban traffic noise. One of the main reasons for this was felt to be that the drive-by noise test procedure did not accurately reflect real world urban driving.For that reason, work on the development of a new noise test procedure that more accurately reflected real world driving began within the United Nations Economic Commission for Europe (UN ECE) Working Party on Noise (GRB) in 2000.It took many years for this new test procedure to be fully developed and validated, but it was finally introduced into the UN ECE on permissible sound levels, Regulation No. 51.02, by Supplement 5, which was published in 2007.
To gather data on how existing vehicles performed when tested to the new noise test procedure, it was initially introduced into ECE 51.02 alongside the old noise test. For type approval, the vehicle was tested to the old noise test procedure and the existing sound level limits were applied. However, at the same time, the vehicle was also tested to the new noise test procedure and the result recorded. To obtain additional data, the European Commission also amended the EC Directive on permissible sound levels to adopt the same procedure (refer to 2007/34/EC).
Once the European Commission had gathered sufficient data, they drafted a new EU Regulation on sound levels that would repeal and replace 70/157/EEC. In addition to introducing the new noise test procedure, the draft Regulation also included the following:
- Reduced sound level limits, with reductions introduced in two phases.
- New Additional Sound Emission Provisions (ASEP) to ensure that the sound levels emitted by vehicles are controlled during all normal driving conditions, not just when tested in accordance with the new noise test procedure.
- New requirements on Acoustic Vehicle Alerting Systems (AVAS) for fitment to "quiet" vehicles, such as pure electric and hybrid electric vehicles.
- Requirements on compressed air noise that are carried over from 70/157/EEC.
- Requirements on replacement exhaust systems for M1 and N1 category vehicle that are carried over from 70/157/EEC, but updated to reflect the new noise test procedure.
This draft Regulation was subject to much debate within the European Council and the European Parliament, especially with regard to the applicable sound level limits and their mandatory application dates. However, a revised version of the draft was finally adopted by the European Council on 20th February 2014, endorsed by the European Parliament on 2nd April 2014 and officially published as EU Regulation No. 540/2014 on 27th May 2014.
New EU Regulation No. 540/2014 on the sound level of motor vehicles and of replacement silencing systems represents the most significant change in the European legal requirements on sound levels for almost 20 years. The new requirements introduced by this Regulation can be summarised as follows:
- New noise test procedure - The new noise test procedure, which was first introduced into EC legislation by 2007/34/EC, is intended to be more representative of real world urban driving. Vehicles with a GVW not exceeding 3,500 kg are subject to both an acceleration test and a constant speed test, with the results from both tests combined to give the final result, whilst vehicles with a GVW exceeding 3,500 kg are only subject to an acceleration test.
- New noise test limits - The new Regulation specifies different sound level limits depending on the vehicle category, engine power, maximum mass and power to mass ratio. For each vehicle classification, three phases of sound level limits are specified. Compliance with the Phase 1 limits becomes mandatory for new types of vehicle from 1st July 2016. Compliance with the Phase 2 limits, which are 1 or 2 dB(A) lower than the Phase 1 limits depending on the vehicle classification, becomes mandatory from 1st July 2020 for new types of vehicle and from 1st July 2022 for all vehicles, although these dates are delayed until 1st July 2022 and 1st July 2023 respectively for N2 category vehicles. Compliance with the Phase 3 limits, which are a further 1 or 2 dB(A) lower than the Phase 2 limits depending on the vehicle classification, becomes mandatory from 1st July 2024 for new types of vehicle and from 1st July 2026 for all vehicles, although these dates are delayed until 1st July 2026 and 1st July 2027 respectively for M3, N2 and N3 category vehicles.
- Additional Sound Emission Provisions (ASEP) - The new additional sound emission provisions introduced by the Regulation apply to M1 and N1 category vehicles. The additional sound emission provisions specify that, in addition to meeting the specified sound level limits when tested in accordance with the new noise test procedure, the manufacturer must also demonstrate that the vehicle's sound level emissions do not significantly differ from the recorded test result under typical on road driving conditions. The main purpose of these provisions is to prevent the use of devices or control strategies that reduce the vehicle's sound level emissions under specific conditions, i.e. when following the noise test procedure, but which are ineffective under other conditions.
- Acoustic Vehicle Alerting System (AVAS) - Acoustic vehicle alerting systems are sound generating systems that are fitted to "quiet" vehicles, such as pure electric and hybrid electric vehicles, to signal the vehicle’s presence to pedestrians, especially visually impaired pedestrians, and other road users. The new Regulation includes some basic requirements on the AVAS and its operation. The fitment of AVAS to pure electric and hybrid electric vehicles becomes mandatory from 1st July 2019 for new types of vehicle and from 1st July 2021 for all new vehicles. Any AVAS systems that are voluntarily fitted to vehicles prior to those dates will be required to comply with the requirements specified in the Regulation.