Technical support for the impact assessment on Euro 5 step of L-category sound emissions level limits : final report.
Date: 2022-06-03
Institutions: Directorate-General for Internal Market, Industry, Entrepreneurship and SMEs
Subjects: motor vehicle, noise level, noise pollution, noise protection, report, sample survey, two-wheeled vehicle

Technical support for the impact 
assessment on Euro 5 step of L-
category sound emissions level 
limits 

Final Report 

J. Arévalo, J.Conesa, C. Dobarro, J. Neto, X. Montané, X. Casals, C. Vollath, J.J. García 
November 2021 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
EUROPEAN COMMISSION 

Directorate-General for Internal Market, Industry, Entrepreneurship and SMEs 
Directorate I — Ecosystems IV: Mobility & Energy Intensive Industries 
Unit I.2 — Mobility 

E-mail:  grow-i2@ec.europa.eu 

European Commission 
B-1049 Brussels 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
EUROPEAN COMMISSION 

Technical support for the impact 
assessment on Euro 5 step of L-
category sound emissions level 
limits  

Final Report 

Directorate-General for Internal Market, Industry, Entrepreneurship and SMEs  
Mobility   

2022 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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PREFACE 

Noise is an important public health issue. It has negative impacts on human health 
and  well-being  and  is  a  growing  concern.  According  to  the  World  Health 
Organisation  (WHO),  noise  is  second  only  to  air  pollution  in  the  impact  it  has  on 
health. It is a major cause, not only of hearing loss, but also of heart disease, learning 
problems in children and sleep disturbance. Yet, according to T&E traffic noise could 
easily be halved, with existing technology, if more stringent limits were adopted. 

Additionally, the WHO recommends policy-makers implementing suitable measures 
to reduce noise exposure from road traffic to reduce average noise exposure, night 
noise exposure and overall health effects in the population exposed1. 

The permissible sound level of L-category vehicles is part of the EU vehicle  type 
approval legislation, as laid down in Regulation (EU) 168/2013*2019/129. EURO 4 
step sound level limits and test procedures for all vehicle subcategories are defined 
in Annex VI to this Regulation. 

Supplementing Regulation (EU) 134/2014*2018/295 is the Delegated Act related to 
in 
environmental  and  propulsion  unit  performance  requirements  (REPPR),  and 
Annex IX includes the test requirements regarding noise for L-category vehicles. 

Both  frame  Regulation  (EU)  168/2013*2019/129  and  Supplementing  Regulation 
(EU)  134/2014*2018/295  refer  to  UNECE  Regulation  No.9.08  as  test  method  for 
noise emission tests on L2e, L5e, L6e, L7e category vehicles and UNECE No.41.04 
as test method reference for noise emission tests on L3e category motorcycles. 

Euro  5  step  sound  level  limits  have  not  been  defined  yet  by  the  European 
Commission. After reaching a conclusion in this study, the Commission will propose 
the Euro 5 step sound level limits. 

Global  objective  of  the  project  for  the  Technical  Support  for  the  Impact 
Assessment on Euro 5 step of L-Category Sound Emissions Level Limits. 

The objective of the work reported herein is to assist DG GROW with the evaluation 
of possible new sound level limits for L-category vehicles. 

In order to do so, the following sub-objectives are defined: 

a)  Evaluation of the sound level of the state-of-the-art vehicles 
b)  Ranking of the different sources of noise of the vehicle 
c)  Proposal of new sound-level limits 

This document contains the results obtained in Tasks 1, 2, 3, 4 and 5 of the project 
‘Technical support for the impact assessment on Euro 5 step of L-Category sound 
emissions level limits’. 

 
 
 
 
 
(Specific Contract SI2.831058 (Technical support for the impact assessment on Euro 
5 step of L-category sound emissions level limits implementing Framework contract 
No 688/PP/2018/FC) 

The  document  is  formed  by  the  concatenation  of  six  individual  project  tasks 
generated to cover the following activities: 

  TASK 1 – Subtask 1.1: Feedback gathering 
  TASK 1 – Subtask 1.2: Literature review 
  TASK 2: Verification of sound level limits 
  TASK 3: Noise source ranking 
  TASK 4: CBA 
  TASK 5: Proposal for sound emission limits 

The activities for each task are described herein  in the corresponding chapter with the same 
number. 

The conclusions of each task are presented at the end of each chapter in this report. 

6 

 
 
 
 
 
 
Table of Contents 

1.  Estimation of L-categories fleet representativeness in sound emissions11 

1.1. Stakeholder’s profile ........................................................................................ 11 

1.2. Questions ....................................................................................................... 12 

1.2.1. Question No. 1 - In your opinion, which is the relevance given at this moment to 
noise pollution caused by road traffic? ..........................................................................12 
1.2.2. Question No. 2 - According to your point of view, which of the following factors are 
causing noise disturbances from motorcycles, tricycles and quadricycles on public 
roads? ..........................................................................................................................14 
1.2.3. Question No. 3 - Do you think that the currently adopted sound emission test 
procedures for L-category vehicles, set out in the UNECE Regulations, reproduce the 
actual driving conditions found in public roads? ............................................................17 
1.2.4. Question No. 4 - For vehicles where UNECE Regulation No. 41 applies, and 
according to your understanding, which of Lwot and Lurban limits is more significant when 
translated to the actual sound emission level produced by L3e-category vehicles on 
public roads? ................................................................................................................20 
1.2.5. Question No. 5 - Do you think that the existing test procedures and worst- case 
criteria regarding PMR, tire configuration, wheel slip, wheel lift up and riding modes are 
clearly defined and understandable for all technical services and that there is a uniform 
application of them? ......................................................................................................22 
1.2.6. Question No. 6 - According to your judgement, do current ASEP test procedures 
ensure, for vehicles where this procedure is applicable, a complete evaluation of the 
vehicle’s sound emission for the most common driving scenarios? ..............................24 
1.2.7. Question No. 7 - Which of the following changes on ASEP procedure do you think 
that would result in a more comprehensive evaluation of the sound emission for the 
concerned vehicle categories? .....................................................................................26 
1.2.8. Question No 8 - Do you think that the tampering (e.g. fitting of non- approved 
exhaust systems) on L-category vehicles resulting in an increase of their sound 
emission levels makes a negative social perception of such vehicles? .........................29 
1.2.9. Question No 9 - According to your point of view, which of the following vehicle 
categories are more likely to be tampered in a way that increases their sound emission 
level? ............................................................................................................................31 
1.2.10. Question No 10 - According to your perception, are motorcycles, tricycles and 
quadricycles more likely to be driven in an aggressive way than other categories of 
vehicles? ......................................................................................................................33 
1.2.11. Question No 11 - In your opinion, what is the effect of an aggressive driving style 
on the noise pollution created by L-category vehicles in urban and extra-urban 
environments? ..............................................................................................................35 
1.2.12. Question No 12 - European Union cities are progressively reducing the access 
and maximum speeds on congested traffic areas based in pollutants emissions criteria. 
Do you think that this policy contributes also to limit the access to the clean air zones to 
motorcycles, tricycles and quadricycles having a high level of sound emissions? .........37 
1.2.13. Question No 13 - Electric L-category vehicles are increasing their presence on 
streets and roads. Which percentage of EV do you estimate to find in your country fleet 
in the future for the indicated vehicle categories and timelines? ....................................38 

 
 
 
 
1.2.14. Question No 14 - Which impact do you think that a future increasing percentage 
of electric L-category vehicles among your country’s fleet would produce on the 
perceived noise pollution? ............................................................................................40 
1.2.15. Question No 15  -  Please  indicate  which  in  your  opinion  are  the  main sound 
emissions sources found on the following types of vehicles: ........................................43 
1.2.16. Question No 16 - In which of the following vehicle’s parts or systems do you 
think that it is more likely to find cost-effective solutions in order to reduce the sound 
level of L-category vehicles?.........................................................................................45 
1.2.17. Question No 17 - From your experience, for motorcycles, tricycles and 
quadricycles using absorbent fibrous materials in its exhaust silencers what is the 
significance of this feature for the improvement on vehicle’s  sound emission levels? ..47 
1.2.18. Question No 18 - According to your experience, in which of the following 
categories absorbent fibrous materials are more commonly used to reduce sound 
levels? ..........................................................................................................................49 
1.2.19. Question No 19 - Do you think that the technologies available at this moment 
allow for an improvement of sound emission levels of L-category vehicles? .................51 
1.2.20. Question No 20 - In your opinion, which existing or new technologies would 
allow for a decrease of the sound emission level  of  motorcycles, tricycles and 
quadricycles?................................................................................................................53 
1.2.21. Question No 21  -  In  your  opinion,  for  which  of  the  following  L-category 
vehicles is compliance with the existing sound emission limits more difficult? ............55 
1.2.22. Question No 22 - According to your point of view, for which of the following 
vehicle categories a reduction on the approval sound emission limits would have a 
greater positive impact on road traffic noise pollution? ..................................................57 
1.2.23. Question No 23 - Could you indicate, according to your understanding, which 
sound level limit reduction (if any) should apply to each of the following categories? ....59 
1.2.24. Question No 24 - According to your point of view, how big do you think the 
financial impact of lowering Euro 5 sound emission limits would be on motorcycles, 
tricycles and quadricycles manufacturers? ...................................................................62 
1.2.25. Question No 25 - What would be, from your understanding, the cost/benefit ratio 
threshold in case that lower sound emission level regulatory limits applied? ................64 
1.2.26. Question No 26 - According to your understanding, what would be the maximum 
increase in vehicle’s selling price tolerated by the market for motorcycles, tricycles and 
quadricycles with a lower sound emission level? ..........................................................67 
1.2.27. Question No 27 - According to your point of view, in the event of new lower 
sound emission level limits being defined, which would be the timeframe needed by the 
manufacturers to implement the modifications in their vehicles to fulfil the new limits? .69 
1.2.28. Question No 28 - In case sound level limits were substantially lowered, do you 
think this would lead to an increase of the tampering practices of the concerned L-
category vehicles by users? ..........................................................................................73 
1.2.29. Question No 29 - Do you think that lowering sound emission level limits could 
translate into an improvement of the sound emission level values collected through in-
use controls? ................................................................................................................75 
1.2.30. Question No 30 - In your opinion, which bodies should be in charge of the in-use 
control of sound emission levels on the existing fleet of L-category vehicles? ..............77 
1.2.31. Additional remarks and comments ....................................................................79 
1.2.32. General conclusions .........................................................................................80 

1.3. Literature review ............................................................................................. 81 

1.3.1. Vehicle life expectancy .......................................................................................81 
1.3.2. Considerations on noise control technology for powertrain noise reduction in l-
type vehicles .................................................................................................................81 
1.3.3. Vehicle average mileage (per category) – (information from year 2015) .............86 
1.3.4. Extra information/graphs .....................................................................................87 
1.3.5. Registrations per country and per vehicle category .............................................90 

8 

 
1.3.6. Average speed in EU cities (information from year 2007) ...................................93 
1.3.7. Speed limits EU cities: (information from year 2015) ...........................................94 
1.3.8. Number of EU cities with low speed areas (information from year 2019) .............95 
1.3.9. Review of information regarding PTI (periodical technical inspections in Europe.
 .....................................................................................................................................96 
1.3.10. Urban and extra-urban noise levels ..................................................................99 
1.3.11. Health impact of exposure to environmental noise .......................................... 102 
1.3.12. Considerations about the annoyance from scooters and motorbikes noise ..... 107 
1.3.13. Environmental impact of road noise on biodiversity ......................................... 110 

2.  Verification of sound level limits ............................................................. 113 

2.1. Vehicle testing – sound level measurements ................................................ 113 

2.1.1. Vehicle’s selection justification .......................................................................... 113 
2.1.2. Category definition ............................................................................................ 114 
2.1.3. Acronyms and symbols ..................................................................................... 115 

2.2. Testing procedures ...................................................................................... 116 

2.2.1. UN Regulation 41.05 proposal operating conditions.......................................... 120 
2.2.2. UN Regulation 09.08 operating conditions ........................................................ 122 

2.3. Testing results .............................................................................................. 125 

2.3.1. UN Regulation 41.04 ......................................................................................... 125 
2.3.2. UN Regulation 09.08 ......................................................................................... 127 
2.3.3. UN Regulation 41.05 ......................................................................................... 128 

2.4. Summary of EU WVTA results sampling per L-vehicle sub-category .......... 131 

2.4.1. Average results according to UN Regulation No. 41.04 .................................... 131 
2.4.2. Average results according to UN Regulation No. 09.08 .................................... 131 

2.5. Conclusions ................................................................................................. 132 

3.  Noise source ranking ............................................................................... 133 

3.1. Vehicle’s selection justification ..................................................................... 133 

3.2. Testing procedures ...................................................................................... 134 

3.3. Results ......................................................................................................... 138 

3.3.1. Vehicles tested according to the UN Regulation No. 41.04 ............................... 138 
3.3.2. Vehicles tested according to the UN Regulation No. 09.08 ............................... 166 

3.4. Conclusions ................................................................................................. 171 

4.  Cost Benefit Analysis ................................................................................ 176 

4.1. Introduction ................................................................................................... 176 

4.1.1. Objective ........................................................................................................... 176 
4.1.2. Cost benefit analysis approach ......................................................................... 176 

4.2. CBA Model ................................................................................................... 177 

4.2.1. Scope ............................................................................................................... 177 
4.2.1. Noise level reduction ......................................................................................... 177 
4.2.2. Socio-economic benefits ................................................................................... 180 

 
 
4.2.3. Socio-economic cost ......................................................................................... 182 
4.2.4. Discount rate and Net Present Value ................................................................ 183 

4.3. Scenarios ..................................................................................................... 183 

4.3.1. Common assumptions ...................................................................................... 184 
4.3.2. Definition of scenarios ....................................................................................... 184 

4.4. Discussion of results .................................................................................... 189 

4.4.1. Differences between scenarios ......................................................................... 190 
4.4.1. Comparison of results with earlier work ............................................................. 192 

4.5. Conclusions ................................................................................................. 195 

5.  Proposal for limit values ........................................................................... 196 

5.1. General conclusions ..................................................................................... 196 

5.1.1. Scenario A: 0 dB reduction (Lurban) – Increased enforcement only: .................... 196 
5.1.2. Scenario B: 2 dB reduction (Lurban) – Moderate: ............................................ 197 
5.1.3. Scenario C: 4 dB reduction (Lurban) – Ambitious: ................................................ 198 
5.1.4. Scenario D: 4 dB reduction: 2 dB reduction in 2024 + 2 dB reduction in 2026 
(Lurban) – Stepwise: ................................................................................................... 198 

6.  References: ................................................................................................ 201 

10 

 
 
 
1. Estimation  of  L-categories  fleet  representativeness  in 

sound emissions 

In order to evaluate the noise emission level of the current motorcycle, tricycle and quadricycle 
European fleet and to analyse the potential improvement that current and future technologies 
may enable in this field a stakeholder consultation has ben carried out. The questionnaire has 
been designed to obtain relevant information regarding topics such as: 

  Perception  on  the  significance  of  motorcycle  noise  emission  on  the  global  noise 

pollution level 

  Perception on the significance of tricycle and quadricycle noise emission on the global 

noise pollution level 

  Convergence  of  the  existing  homologation testing methods  with special  attention  to 

ASEP criteria, when applicable 

  Suitability of the existing test procedures to fairly evaluate all type of L-category vehicle 

sub-categories and configurations 

  Available  and  detailed  data  on  approval  test  results  for  all  L-category  vehicle 

categories 

  Available and detailed data on in-use test control results for L-category vehicles 

  Availability  and  diversity  of  technologies  to  lower  the  different  sources  of  noise  on 

motorcycles, tricycles and quadricycles 

 

Impact of in-use noise level control on noise pollution caused by motorcycles. 

1.1. Stakeholder’s profile 

The questionnaire was addressed to 336 stakeholders with a very large spectrum of profiles 
covering  approval  authorities,  technical  services,  consumer  organizations,  governmental 
bodies,  manufacturers  associations,  L-category  vehicles  manufacturers  and  replacement 
exhausts  systems  manufacturers.  The  number  of  received  answers  has  been  33.  The 
questionnaire has been answered by the following organizations: 

UTAC  CERAM,  FEMA,  Ayuntamiento  de  Madrid,  European  Commission  -  Joint  Research 
Center  (JRC),  Swiss  Federal  Roads  Office  (FEDRO),  Polaris  Inc.,  CERTH/HIT,  Norwegian 
Public  Roads  Administration,  Umweltbundesmat,  Applus+,  Federation  Internationale  de 
Motocyclisme, Applus+ Automotive, ACEM, MV Agusta Motor S.p.A., Yamaha Motor Co., Ltd., 
Ducati  Motor  Holding,  KTM  AG,  Honda,  Ministry  of  Transport  and  digital  infrastructure  of 
Germany  (BMVI), TÜV SÜD  Czech  s.r.o,  RDW,  Ministry  of  ecological  transition,  Ministry  of 
transport  and  Construction  of  the  Slovak  republic,  IDIADA,  IMMA,  Triumph  Motorcycles, 
Kawasaki Motors Europe N.V, and LCOE. 

We  can  divide  these  organizations  into  four  big  branches:  Governmental  bodies,  technical 
services, industry and other organizations. 

The percentage of each stakeholder profile answering to the questionnaire is represented in 
the following graph: 

 
 
Figure 1: Stakeholder’s profile 

The number of received answers is about 10 % from the total number of stakeholders to which 
the  questionnaire  was  addressed,  but  the  representation  of  the  different  profiles  is  quite 
balanced. 

1.2. Questions 

1.2.1. Question No. 1 - In your opinion, which is the relevance given 
at this moment to noise pollution caused by road traffic? 

Options: Null, low, medium, high, I don’t know. 

Figure 2: Answers to question 1. 

Additional comments 

"I think that road traffic contributes a lot to the noise pollution of our cities and countryside. It 
is true that the proximity of an airport, or the proximity of works on the public highway will tend 
to diminish its role, however, given the increasing number of vehicles, it is necessary to attach 
great importance to it." – UTAC CERAM 

12 

 
 
 
 
 
“Sound caused by road traffic can be experienced almost all day and night long in many places 
in Europe, especially in the more populated areas. In many, but not all, places noise emission 
has  an  impact  on  wellbeing  and  health  of  citizens.  However,  there  is  also  an  element  of 
perception, related to time of the day, day of the week, existence of other sources of sound or 
noise  and  one’s  own  preferences.  Loud  noise  can  be  experienced  by  one  person  as  very 
unpleasant or even harmful, while the same noise doesn't bother another person” - FEMA 

“Exists regulatory acts with limits and the new methods of testing are under development”  - 
Anonymous 

“It greatly adds to the noise pollution that citizens suffer in urban environments” – 

European Commission – Joint Research Center (JRC) 

“Annoying noise to a big part of the population” - Swiss Federal Roads Office (FEDRO) 

“Non-motorcycle operators are generally dis-satisfied by the noise level of some motorcycles 
that pass by. Some motorcycle operators are also dis-satisfied by the noise”- Polaris Inc. 

“Noise pollution doesn't need any sensor to be measured by anybody. Thus, anybody could 
be annoyed and could talk about it” – UTAC CERAM 

“Noise is mostly considered a nuisance rather than a threat to health. Vehicle manufacturers 
regularly  construct  vehicles  to  be  more  noisy  than  necessary.  In  fact,  money  is  spent  to 
increase sound (aka noise) and manufacturers praise the impressive sound of their vehicles.” 
– Umweltbundesamt 

"In Spain noise pollution is checked in PTI centres (motorcycles and mopeds only), but in other 
countries it is not done. A few years ago, the police carried out random checks on the streets 
(only on mopeds and motorbikes), but today they are no longer" 

– Applus+ 

“The  polluting  noise  must  be  checked,  mandatorily  at  ITV  stations,  for  all  motorcycles  and 
mopeds, but it is only done in a few countries (Spain is one of them)” – Applus+ 

Automotive 

“ACEM  recognises  an  increase  of  public  attention  on  traffic  noise  of  cars,  trucks  and 
motorcycles in the recent months (in central Europe)” - ACEM 

“We do not have information” - MV Agusta Motor S.p.A. 

“It  is  quite  difficult  to  collectively  determine  how  relevant  road  traffic  is  to  noise  pollution 
because it is dependent on areas, time, and weather conditions. Rather, it is appropriate to 
evaluate the relevance based on quantitative indices” - Yamaha Motor Co., Ltd. 

“I nevertheless recognise an increase of public attention in central Europe on traffic noise of 
cars, trucks and motorcycles in the recent months” - Ducati Motor Holding 

“There are very few complaints which mostly revolve around peak noise events when they do 
occur rather than constant noise” – FIM 

“However,  KTM  recognises  an  increasing  interest  in traffic  noise  in general  by the  public  in 
central Europe” – KTM AG 

“Due to recent press coverage in centre Europe on traffic noise of cars, trucks and Motorcycles 
it's more in today's public attention” – HONDA 

 “Because of the big number of vehicles in urban areas during the hole week, the big number 
of  motorbikes  inside  touristic  areas  during  weekend  and  the  high  number  of  silencer-
manipulated motorbikes in combination with the driving style of some drivers a lot of people 
are highly annoyed on this topic” - Ministry of Transport and digital Infrastructure of Germany 
(BMVI) 

 
 
“We have a lot of new vehicles with low sound emission level, but also quite a lot old one which 
are not fulfilling last stages of limits (especially here in central and eastern Europe) - TÜV SÜD 
Czech s.r.o. 

“Currently there is a lot going on in relation to sound emissions. Especially in places and areas 
where motorcycles drive a lot. - RDW 

The  technical  requirements  of  the  vehicle  test  are  inappropriate.  Approved  tests  of  moving 
vehicle noise, as well as stationary measurements, do not guarantee acceptable noise in all 
modes of use of particularly used vehicles." – TF (individual) 

“Other issues like tyre and brake particles generate higher concern.” - IDIADA 

"Euro 4/5 motorcycles are not the main factor of sound emissions on road (smallest amount of 
traffic). Old aged exhausts and aggressive behaviour are the most impacts." - Anonymous 

“IMMA  nevertheless  recognises  an  increase  of  public  attention  in  central  Europe  on  traffic 
noise of cars, trucks and motorcycles in the recent months - IMMA 

“Until very recently I would have rated this as low to medium however recent issues across 
Europe has heightened this subject.” - Triumph Motorcycles 

Conclusions 

There is a strong trend on the relevance given at this moment to noise pollution caused by 
road traffic, and it seems clear that it is a sensitive topic, since half of the collected answers 
(50 %) indicate a high level of concern and the addition of medium and high relevance answers 
make for a vast majority of opinions (88 %). 

1.2.2. Question No. 2 - According to your point of view, which of the 
from 

following 
motorcycles, tricycles and quadricycles on public roads? 

factors  are  causing  noise  disturbances 

Options:  Tampering,  bad  maintenance,  aggressive  driving,  non-conforming  exhausts,  high-
mileage or old vehicles, high sound emission limits, lack of exhaustive regulatory requirements, 
lack of awareness campaigns for riders and drivers, insufficient in-use controls, I don’t know, 
other 

14 

 
 
Answers received as other 

Figure 3: Answers to question 2. 

The number of motorcycles on certain (scenic) roads on certain times (weekend, holidays); 
noise  at  high  rpm;  violation  of  local  traffic  regulations  (i.e.  speeding,  causing  unnecessary 
noise); lack of suitable, trained, policing. 

Additional comments 

"The vehicles on the market are homologated and shall not be noisy as they are. The reason 
why they become noisy is due to the use of the users and the transformations made." – UTAC 
CERAM 

“Noise disturbance by motorcycles (and other vehicles) is not caused by just one factor. It is a 
combination  of  technical  aspects  (tampering,  non-conforming  exhausts,  exhausts  and 
motorcycles that are legal, but produce a loud volume in certain revolutions per minute, etc.) 
and behavioural aspects like too fast accelerating, riding in too low gear, the fact that many 
riders come to the same roads on the same time which causes a large number of motorcycles 
using that roads.” – FEMA 

"Aggressive driving, tampering and non-conforming exhaust - L3 category of vehicles 

- main problems. Tampering, non-conforming exhaust - mopeds" – Anonymous 

"Existe  un  elevado  número  de  motocicletas  que  circulan  con  sistemas  de  escape  no 
homologados o modificados. En general los sistemas de escape no originales se diseñan para 
que el usuario final pueda manipularlos fácilmente y poder circular sin el ""DB-Killer"". Mejorar 
la regular la emisión de los certificados de homologación de estos elementos. 

Debe incrementarse el control sobre los escapes ""no originales"" homologados. 

La técnica actual permite diseñar y fabricar motocicletas más silenciosas con lo que se podrían 
reducir los límites considerablemente, pero en general, los conductores prefieren motocicletas 
más ruidosas." – Ayuntamiento de Madrid 

 
 
 
“Many  motorbikes  are  tampered  with,  increasing  the  noise  pollution  by  these  vehicles. 
Unfortunately, there is insufficient control on this.” European Commission. Loud motorcycles 
are  generally  due  to  consumer  modifications  or  tampering.  Aggressive  driving  is  less  of  a 
contributor than tampering but is a concern from a safety and perception standpoint.” – Polaris 
Inc. 

"Type approval Regulations are fine. Regardless the vehicle category none of them  - when 
brand new - are a real noise disturbance. 

But  how  much  it's  easy  to  modify  exhaust  system?  Too  much.  And  that's  the  start  of  the 
problem considering that there is no actual conformity check on road." – UTAC CERAM 

"Regulatory  requirements  cover  by  design  only  a  small  part  of  real  driving  situations.  The 
regulations  are  not  well  suited for  in-use  control. The  absurdity  of the  current regulations  is 
apparent by a look at the vehicle's papers which could state a stationary noise level of more 
than 100 dB(A). Is there any sensible explanation for this besides the fact that the regulations 
are largely dictated by the manufacturers? 

The  whole      setup      is      designed      to      legalize      the      ""business      model      sound"".      -
Umweltbundesamt 

 “Sound limits are set in low RPM while noise disturbances occur in high RPM” – 

Applus+ 

“Type approved motorcycles, used in a normal manner according to the applicable traffic rules 
are not loud. OEM spec. motorcycles are not the cause of disturbances.” 

– ACEM 

“We believe that there are sufficient Regulations and if the motorcycles are conforming, they 
do not cause noise disturbance.” – MV Agusta Motor S.p.A. 

“For OEM  vehicles,  examination of sound  levels  under  wide  range  of driving  conditions  are 
covered  by  ASEP  of  UNR41-04.  We  consider  tampering  (e.g.,  installation  of  unapproved 
exhausts) and inappropriate riding behaviours as factors to be prioritized for addressing noise 
pollution.” - Yamaha Motor Co., Ltd. 

“In my opinion OEM motorcycles are not the cause of noise disturbances. OEM motorcycles 
used in a normal manner according to the applicable traffic rules are not loud.” – Ducati Motor 
holding 

“Most  complaints  around  noise  refer  to  loud  exhausts  on  aggressively  ridden  motorcycles. 
Standard exhausts are not excessively loud.” - FIM 

“Type approved motorcycles, used in a normal manner according to the applicable traffic rules 
are not loud. OEM spec motorcycles are not the cause.” - Honda 

“In the opinion of all experts in Germany, the reduction of noise limits or the introduction of new 
regulations for motorcycles will only lead to lower real emissions if the tendency to manipulation 
can be stopped. Almost without exception, complaints about excessively loud motor vehicles 
are triggered by technical changes / manipulations (e.g. removal of silencer inserts, installation 
of  non-approved  silencers  or  installation  of  additional  control  units)  or  by  reckless  behavior 
caused  by  driving  at  extremely  high  rpm  or  speed.”  -  Ministry  of  Transport  and  digital 
Infrastructure of Germany (BMVI) 

“On motorbikes is quite easy replace exhaust system and checking if "approval" mark on this 
replaced silencer/exhaust system is true or not is not done (by police or during PTI) (experience 
from CZ, marked exhaust is enough, nobody takes care if any papers are behind)” - TÜV SÜD 
Czech s.r.o. 

“The  main  annoyances  are  the  vehicles  with  excessive  sound  emissions  due  to  before 
mentioned reasons.” - RDW 

16 

 
“The engine, transmission, intake and exhaust mufflers are very easily accessible on 2-wheel 
vehicles and have a direct impact on the dynamic performance of the vehicle to the detriment 
of environmental performance.” - Ministry of ecological transition 

 "Inaccurate  and  insufficient  requirements  of  obligations  to  manufacturers  of  replacement 
exhaust systems. 

Poor control of the installation of replacement exhaust systems. Poor control of exhaust system 
modifications. 

Insufficient knowledge and training of persons in charge of vehicle control." - Individual 

“Noise complaints associated to L-vehicles are normally related to improper use of the vehicle 
in urban environments, driving behaviour or tampering” - IDIADA 

"Loud noises caused mainly from non-conform vehicles, parts and driving behaviour. The latest 
ASEP Amend/Suppl. of UNECE R41 covers more parameters, was absolutely necessary for 
the ""driving behaviour"." - Anonymous 

“Type approved motorcycles used in a normal manner according to the applicable traffic rules 
are not loud. OEM spec motorcycles are not the cause.” - IMMA 

“The non-approved exhaust is the bigger problem to the high noise level of the traffic.” 

– LCOE 

Conclusions 

Non-conforming exhausts, with a 20 % of answers, are understood as the most relevant factor 
regarding  noise  disturbances  on  public  roads,  and  tampering  follows  closely  with  a  18  %. 
Rider’s behavior makes also for a substantial part of the answers, given that the addition of 
both aggressive driving and lack of awareness campaigns for riders and drivers make for a 31 
% of answers. Insufficient in-use controls, with a 14 % of answers is also shown as a relevant 
factor. On the other side, the percentage of answers considering high sound emission limits 
and lack of exhaustive regulatory requirements as a contributing factor to noise annoyance is 
low, with a 3 % of the choices, for both topics. 

1.2.3. Question No. 3 - Do you think that the currently adopted sound 
emission  test  procedures for  L-category  vehicles, set  out  in 
the  UNECE  Regulations,  reproduce 
the  actual  driving 
conditions found in public roads? 

Options: Yes, partially, no, I don’t know 

 
 
 
Additional comments 

Figure 4: Answers to question 3. 

"Tests with target accelerations are very good, and in my opinion, represent common urban 
driving conditions. Nevertheless, I find that certain speed conditions, high speeds for example, 
are not envisaged." – UTAC CERAM 

“The existing WOT test method measures just the sound emission in a very small bandwidth 
of RPM. ASEP 2.0 (UN ECE R41.05) should bring a more realistic view.” 

– FEMA 

“Style of driving should be better represented in tests” – Anonymous 

“Las condiciones establecidas actualmente para la prueba de aceleración, en muchos casos, 
no  se  ajustan  a  las  condiciones  reales  de  conducción.  Nos  encontramos  con  bastantes 
motocicletas homologadas en la prueba de Pass-By con relaciones de marcha muy elevadas, 
con lo que los resultados no se corresponden con la conducción real. Sin embargo, con la 
normativa anterior esas mismas motocicletas no habrían cumplido los límites.” – Ayuntamiento 
de Madrid 

“Additional Sound Emission Procedure (ASEP) should be further developed (which is actually 
the case).” - Swiss Federal Roads Office (FEDRO) 

 “Depend of Regulation. 41 is fine with ASEP and ongoing amendments. 9 and 63 are probably 
less representative and should be improved.” – UTAC CERAM 

“The noise occurs while the engine accelerates, especially with the motorcycle stopped, and 
this is not checked in the test procedures” – Applus 

“The  most  annoying  noise  occurs  at  the  time  of  acceleration,  even  with  the  motorcycle  or 
moped stopped, and this point is not checked” – Applus Automotive 

"For motorcycles, UN R41-04 series of amendments is currently in place. Our reply is therefore 
based on R41-04, under which only Wide Open Throttle is covered in the ASEP provisions. 
This is the reason why ACEM proposed to enhance the so called ASEP provisions. Under the 
R41-05 series of amendments (adopted at GRBP in September 2020) actual riding conditions 
can be even better reproduced. 

For  what  concerns  NORESS,  latest  amendment  to  UN  R92  aligned  the  requirements  for 
NORESS with original vehicles (back-to-back testing)." – ACEM 

“With the ASEP 2.0 (R41) the vehicle in tested in order to cover almost all possible conditions 
in the areas of urban and suburban traffic.” – MV Agusta SpA 

18 

 
 
"UNR41 has been kept improved in order to evaluate and regulate sound emission levels in 
real-world driving on public roads. 

Under UNR41-04, it is possible to properly reproduce real-world driving conditions through the 
test conditions assuming riding in urban areas as well as the limits according to engine speeds. 

The test procedure in UNR41-05 would make it possible to broaden the control range of vehicle 
speeds, gear shifting and throttle operations further appropriately." YAMAHA MOTOR Co., Ltd. 

"UNR41-04 has been kept improved in order to evaluate and regulate sound emission levels 
in real-world driving on public roads. 

With the upcoming R41-05 series of amendments (adopted at GRBP in September 2020) there 
will be included wide riding conditions." – DUCATI Motor Holding 

“The existing test procedures only measure a narrow range of RPM; however, with such a wide 
diversity of riders, products and use cases, it would be impossible to design a representative 
test cycle of all potential uses.” – FIM 

"For motorcycles, UNECE R41-04 series of amendments is currently applicable for EU WVTA. 

""Partially"" is related to the currently applicable R41-04 with its limited operation range within 
the ASEP test procedure. 

Under the R41-05 series of amendments (adopted at GRBP in September 2020) a much wider 
range of actual operating conditions can be reproduced. 

 For  what  concerns  NORESS,  latest  amendment  to  UN  R92  aligned  the  requirements  for 
NORESS with original vehicles (back-to-back testing)" – KTM AG 

"For motorcycles, UNECE R41-04 series of amendments is currently applicable for EU WVTA. 

""Partially"" is related to the currently applicable R41-04 with its limited operation range within 
the ASEP test procedure. 

“Under the R41-05 series of amendments (adopted at GRBP in September 2020) a much wider 
range of actual operating conditions can be reproduced. 

“For  what  concerns  NORESS,  latest  amendment  to  UN  R92  aligned  the  requirements  for 
NORESS with original vehicles (back-to-back testing)" – HONDA 

"The  document  ""ECE/TRANS/WP.29/GRBP/2020/9  -  (IWG  ASEP)  Proposal  for  a  new  05 
series of amendments to UN Regulation No. 41 (Noise emissions of motorcycles)"" which was 
adopted during 72nd GRBP-Session in Sep. 2020, which hopefully will be adopted in March 
2021 by WP.29 is a step Forward because all realistic driving situations up to 100 km/h and 
80 % of S can be tested. The actual Regulation does only test cruising and wot in some gears. 
The new Version will test all gears and all situations. For the next step in future the ASEP limit 
curve of partial load driving and cruising has to be lowered, because the wot-ASEP-Limit curve 
is too high." - Ministry of Transport and digital Infrastructure of Germany (BMVI) 

"The  tests  do  not  correspond  to  the  actual  use  of  the  vehicle  and  are  easily  bypassed  by 
motorcycle manufacturers, especially replacement exhaust manufacturers. 

The PMR criterion is not fair and the measurement of stationary noise is not good enough." - 
Individual 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles. - Ministry of transport and Construction of the Slovak republic 

“Here the issue is to know how much annoyance is caused by L-vehicles noise used under 
reglementary conditions and under non reglementary conditions.” - IDIADA 

"The additional parameters of last amend./supl. go into the right way. To cover more individual 
driving behaviour the sound limits could be adapted. 

 
 
include  non-conform  driving  behaviour, 

To 
amendments/supplements (higher acceleration and speeds)." - Anonymous 

it  could  be  adapted 

in 

future 

"For motorcycles, UN R41-04 series of amendments is currently in place. our reply is therefore 
based  on  R41-04:  Only  Wide-Open  Throttle  is  covered  in  the  ASEP  provisions,  this  is  the 
reason  why  IMMA  proposed  to  enhance  the  so  called  ASEP  provisions.  Under  the  R41-05 
series of amendments (adopted at GRBP in September 2020) actual riding conditions can be 
better  reproduced.  For  what  concerns  NORESS,  latest  amendment  to  UN  R92  aligned  the 
requirements for NORESS with original vehicles (back-to-back testing)" - IMMA 

 “The move to ASEP 2 will make this more representative. 

Kawasaki Motors Europe N.V. Current UN R41-04 does approach actual riding conditions but 
the range is limited. R41-5 is developed to better represent actual riding conditions.” - Triumph 
Motorcycles 

“The  combination  between  cruise  and  acceleration  measures  are  more  real  that  only  in 
acceleration mode.” - LCOE 

Conclusions 

A  61  %  of  the  received  answers  indicate  that  the  currently  adopted  sound  emission  test 
procedures for L-category vehicles reproduce only partially the actual driving conditions found 
in  public  roads.  The  percentage  of  stakeholders  thinking  that  sound  test  procedures  don’t 
reproduce the actual driving conditions is almost the same as the one thinking that sound test 
procedures reproduce the  actual  driving  conditions,  with a 16  %  and 20 %  of the  answers, 
respectively. 

1.2.4. Question No. 4 - For vehicles where UNECE Regulation No. 
41 applies, and according to your understanding, which of Lwot 
and  Lurban  limits  is  more  significant  when  translated  to  the 
actual  sound  emission  level  produced  by  L3e-category 
vehicles on public roads? 

Options: Lwot, Lurban, I don’t know 

Additional comments 

“Both are not very realistic” – FEMA 

Figure 5: Answers to question 4. 

20 

 
 
“Considero que es más significativo Lwot, pero cuando las condiciones de la prueba establecen 
unas relaciones de marcha demasiado elevadas se desvirtúa la prueba y deja de ser realista” 
– Ayuntamiento de Madrid 

“aggressive driving” - Swiss Federal Roads Office (FEDRO) 

“For my side Lwot is the most representative of potential noise pollution for a L3e. A motorcycle 
which crosses town with a long wide open throttle is definitively the loudest situation, so the 
most  annoying.  When  the  same  vehicle  is  cruising  or  stationary,  I  don't  think  that  relevant 
complains could be collected.” – UTAC CERAM 

“Both are important, but excessive noise as expressed by Lwot is the key problem. I should add 
that the Lwot as reported in UNECE R41 is not very useful as it is measured at relatively low 
RPM. And clearly, a restriction to WOT is not sufficient, because partial load is what is used in 
real traffic almost entirely.” - Umweltbundesamt 

“Lurban is most significant as this represents the vast majority of riding event in urban areas.” – 
ACEM 

 “L_urban  represents  the  vast  majority  of  riding  event  in  urban  areas.”  -  MV  Agusta  Motor 
S.p.A. 

“Lurban is the most significant as it represents urban driving events more completely.” 

- Yamaha Motor Co., Ltd. 

“Lurban, depending on cruise and WOT maneuvers, represents the vast majority of riding event 
in urban areas.” - Ducati Motor Holding 

“The FIM does not have practical expertise on testing road vehicles for homologation.” – FIM 

“Lurban is most significant, as this represents the vast majority of riding events in urban areas.” 
– KTM AG 

“Lurban is representative for the majority of motorcycle noise in normal use in normal traffic. Lwot 
would be more related to inappropriate or maladjusted rider behavior.” 

– Honda 

“A  distinction  must  be  made  between  standard  silencers  and  flap  silencers.  For  standard 
silencers Lwot is important because this is the worst case. Lcrs is then automatically low, which 
also makes Lurban low. In the case of flap silencer systems, the entire test field from 0 to 100 
km/h  and  the  entire  speed  range  of  the  engine  (rpm)  must  be  tested  randomly  and  in 
compliance with the ASEP limit curve(s), since the control of the flaps is the all-decisive SPL 
criterion.” - Ministry of Transport and digital Infrastructure of Germany (BMVI) 

“Both are equally important. There should be a limit for both.” - RDW 

“Noise is preponderant during acceleration.” - Ministry of ecological transition 

"It is necessary to improve UN Regulation no. 92, as follows: 

- 

clearly  prescribe  the  content  of  the  replacement  exhaust  system  manufacturer's 
certificate,  the  content  of  which  should  clearly  describe  the  type,  model  and  variant 
description of all parts forming the replacement exhaust system, an indication of one 
or two (more) mufflers; 

-  disable the preparatory elements on the replacement silencer for easy removal of the 
dB  killer  and  increase  the  responsibility  of  the  constructor  for  easy  unauthorized 
modification (prohibition of the construction of the final choke secured by a small weld, 
easily removable rivet or safety ring); 

 
 
-  and most important of all in UN Regulation no. 92 include the obligation to use noise 
testing  from  UN  Regulation  no.  41.04  series  of  amendment  for  Euro  4  and  Euro  5 
motorcycles. 

The persons responsible for checking the correctness and originality of the exhaust systems 
must be adequately trained. 

series of amendment"- Individual 

 “Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles. - Ministry of transport and Construction of the Slovak republic 

Lurban is most significant, as this represents the vast majority of riding event in urban areas.” - 
IMMA 

“Lwot is what a member of the public would recognize more than LURBAN.” - 

Triumph Motorcycles 

“Lurban  was  specifically  designed  to  represent  the  actual  sound  levels  on  public  roads.”  - 
Kawasaki Motors Europe N.V. 

Conclusions 

This question required some degree of knowledge on UNECE Regulation No. 41 procedures. 
For this reason, a third of the answers were “I don’t know”. 

For the rests of answers Lurban was indicated with a small margin over Lwot (35 % against 30 % 
of answers, respectively) as more significant limit when translated to the actual sound emission 
level produced by L3e-category vehicles on public roads. 

1.2.5. Question No. 5 - Do you think that the existing test procedures 
and  worst-  case  criteria  regarding  PMR,  tire  configuration, 
wheel slip, wheel lift up and riding modes are clearly defined 
and understandable for all technical services and that there is 
a uniform application of them? 

Options: Yes, partially, no, I don’t know 

Figure 6: Answers to question 5. 

Additional comments 

"Yes, I think that the application and performance of the tests are uniform. 

22 

 
 
 
The requirements and worst case may not always be very well understood, however the R41 
text is precise enough." – UTAC CERAM 

“MR, tire configuration, wheel slip, wheel lift up and riding modes are not provided for in the 
current tests.” – FEMA 

“complicated prescriptions” - Swiss Federal Roads Office (FEDRO) 

“Regarding  wheel  lift  up,  riding  mode  or  multiple  exhausts  that  could  be  more  clear  and 
detailed.” – UTAC CERAM 

“Cfr. E.g. §3.2.2 in Annex 7 of the upcoming R41-05 series of amendments: '... If during the 
test unusual riding conditions (such as apparent wheel spin or front wheel lift up) occur, the 
test shall be performed in the next higher gear, ...' 

With the current provisions, there are no specific concerns in this regard. The worst case is to 
be agreed by Technical Service or Type Approval Authority. The TS or “TAA have the power 
to reject a version proposed as worst case by the OEM." – ACEM 

“With the current provisions, there are no specific concerns in this regard.” - MV Agusta Motor 
S.p.A. 

 “With the current provisions, there are no specific concerns in this regard.” - Yamaha Motor 
Co., Ltd. 

"With the current provision there are no specific concerns in this regard. 

With the upcoming R41-05 series of amendments (adopted at GRBP in September 2020) Cfr. 
E.g. §3.2.2 in Annex 7: '... If during the test unusual riding conditions (such as apparent wheel 
spin or front wheel lift up) occur, the test shall be performed in the next higher gear, ...” - Ducati 
Motor Holding 

“The FIM does not have practical expertise on testing road vehicles for homologation.” – FIM 

"Cfr. E.g. §3.2.2 in Annex 7 of the upcoming R41-05 series of amendments: '... If during the 
test unusual riding conditions (such as apparent wheel spin or front wheel lift up) occur, the 
test shall be performed in the next higher gear, ...' 

With the current provisions, there are no specific concerns in this regard. 

The worst case is to be agreed by TS or TAA." – KTM AG 

“The worst case is to be agreed by TS or TAA. TS or TAA have the power to reject a version 
proposed as worst case by the OEM” – Honda 

“The current UN regulation 41 only tests constant speed and wot driving in a few gears and 
the driving modes that are critical from the point of view of the technical service. Due to the 
multitude  of  possibilities  and  the  obligation  to  repeat  individual  tests,  the  amount  of  work 
involved is far too high. Moreover, most real driving situations are not covered by the current 
tests. Through the test of RD-ASEP within the type approval and the CoP-test and the tests of 
the market observation all areas will be tested successively in the future. Should any critical 
driving  conditions  not  tested  during  type  approval  be  negative  during  later  CoP  tests  and 
market monitoring tests, the vehicles would have to be recalled and converted to conform to 
the regulations.” - Ministry of Transport and digital Infrastructure of Germany (BMVI) 

“It is difficult to perform uniform worst case tests with all possible variables.” – RDW 

“PMR is correctly described and the rest is not of great impact.” - Individual 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving  L-category  vehicles.  -  Individual  -  Ministry  of  transport  and  Construction  of  the 
Slovak republic 

 
 
"Cfr. E.g. §3.2.2 in Annex 7 of the upcoming R41-05 series of amendments: '... If during the 
test unusual riding conditions (such as apparent wheel spin or front wheel lift up) occur, the 
test shall be performed in the next higher gear, ...' 

With the current provisions, there are no specific concerns in this regard. 

“The worst case is to be agreed by TS or TAA. TS or TAA have the power to reject a version 
proposed as worst case by the OEM" – IMMA 

 “PMR and tire configuration are suitable. However, the other area above that are in the existing 
regulations  can  lead  to  potential  interpretation  that  may  allow  favourable  results  to  be 
obtained.” - Triumph Motorcycles 

“If there is no common guide for worst-case the interpretation for the Technical Service could 
be different for each other.” - LCOE 

Conclusions 

For this question the percentage of “I don’t know” answers rise to the 35 %, likely due a lack 
of knowledge of the test procedures by a significant part of stakeholders. 

The number of answers where the stakeholder’s opinion is that the existing test procedures 
and worst-case criteria are clearly defined, understandable for all technical services and that 
there is a uniform application is significant, reaching a 35 %, compared to a 15 % of answers 
having the opposite point of view. 

1.2.6. Question  No.  6  -  According  to  your  judgement,  do  current 
ASEP  test  procedures  ensure,  for  vehicles  where  this 
procedure is applicable, a complete evaluation of the vehicle’s 
sound emission for the most common driving scenarios? 

Options: Yes, partially, no, I don’t know 

Additional comments 

“High speeds are not taken into account.” – UTAC CERAM 

Figure 7: Answers to question 6. 

“The RPM bandwidth in the current ASEP test procedure is quite narrow and does not cover 
most common driving scenarios” – FEMA 

“More aggressive acceleration, speed should be taken into account” – Anonymous 

“there is no guarantee that "out of the scope scenarios" will happen on public roads” 

24 

 
 
- 

Swiss Federal Roads Office (FEDRO) 

“Considering the ongoing amendments, that is enough to cover common driving scenarios.” – 
UTAC CERAM 

"We refer here to the Proposal for a new 05 series of amendments to UN Regulation No. 41: 
http://www.unece.org/fileadmin/DAM/trans/doc/2020/wp29grb/ECE- 

TRANS-WP.29-GRBP-2020-09e.pdf" - Norwegian Public Roads Administration 

“Even with an enlarged ASEP control range, there are ample driving conditions which are not 
covered.  Not  covered means that there  is  absolutely  no  limit  and any  sound  emission  be  it 
massive is completely legal. We need to force the manufacturers to take responsibility for the 
sound  emissions  of  their  products  over  the  entire  range  of  possible  driving  conditions.”  – 
Umweltbundesamt 

 “The noise occurs while the engine accelerates, especially with the motorcycle stopped, and 
this is not checked in the test procedures” – Applus+ 

“The  most  annoying  noise  occurs  at  the  time  of  acceleration,  even  with  the  motorcycle  or 
mopeds stopped, and this point is not checked” – Applus+ Automotive 

"Same as for question no. 3, current ASEP test procedure (R41-04) ensures that the vehicle 
is checked over a broad range of engine operation. 

With the upcoming R41-05 series of amendments (adopted at GRBP in September 2020) a 
more complete evaluation for the most common driving events is ensured. For what concerns 
NORESS, latest amendment to UN R92 aligned the requirements for NORESS with original 
vehicles (back-to-back testing)" – ACEM 

“The ASEP 2.0 (R41) make possible to evaluate sound emissions in almost all possible driving 
conditions.” - MV Agusta Motor S.p.A. 

"Under UNR41-04, it is possible to properly reproduce real world driving conditions through 
the test conditions assuming riding in urban areas as well as the  limits according to engine 
speeds. 

The test procedure in UNR41-05 would make it possible to broaden the control range of vehicle 
speeds, gear shifting and throttle operations further appropriately." - Yamaha Motor Co., Ltd. 

“With the upcoming R41-05 series of amendments (adopted at GRBP in September 2020) a 
more complete evaluation for the most common driving events will be ensured.” - Ducati Motor 
Holding 

“The FIM does not have practical expertise on testing road vehicles for homologation.” – FIM 

“same as for question 3” – KTM AG 

“The current R41/04 only tests in WOT, but the recently adopted R41/05 ASEP amendment 
will  even  go  beyond  'most  common  driving  scenarios'  with  testing  possible  in  all  gears,  all 
operation modes, all throttle operations, in a wider rpm & speed range.” – Honda 

“wot and cruising are not the most common driving scenarios. Everything between is the most 
common driving scenario. For a Standard silencer equipped motorbike this is not a problem, 
because of worst case test of wot is done. For flapsystem silencers the test excludes the most 
common driving scenario and open wide window without Limit curve.” - Ministry of Transport 
and digital Infrastructure of Germany (BMVI) 

“The  current  ASEP  test  procedure  has  a  much  lower  coverage  of  the  real  world  driving 
conditions than the newly adopted test procedures. Also, the current ASEP procedure exempts 
vehicles with variable gear ratios or automatic transmission with non-lockable gear ratios and 
if the vehicle has more than one gear, the first gear shall not be used. Besides this the ASEP 
test is performed only with a full throttle acceleration.” - RDW 

 
 
“A revision of R41 is ongoing in Geneva to extend its scope. The second step will be to align 
it with the R51.” - Ministry of ecological transition 

“The PMR criterion is not fair.” - individual 

Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles. - Ministry of transport and Construction of the Slovak republic 

"Not entirely: 

Same as for question no. 3: It ensures that the vehicle is checked over a broad range of engine 
operation. With the R41-05 series of amendments (adopted at GRBP in September 2020) a 
more  complete  evaluation  for  the  most  common  driving  events  is  now  ensured.  For  what 
concerns NORESS, latest amendment to UN R92 aligned the requirements for NORESS with 
original vehicles (back-to-back testing)" - IMMA 

“The move to ASEP 2 will make this more representative.” - Triumph Motorcycles 

“Current UN R41-04 does approach actual riding conditions but the range is limited. R41-5 is 
developed to better represent actual riding conditions.” - Kawasaki Motors Europe N.V. 

“The ASEP open the range of the test and is very useful to control that boundaries.” 

– LCOE 

Conclusions 

From the percentage of received answers it seems clear that the perception for a wide number 
of stakeholders is that ASEP represents only partially the most common driving scenarios (55 
% of answers). It is also relevant the percentage of answers considering ASEP as sufficiently 
representative. 

It’s  worth  saying  that  some  of  the  additional  remarks  refer  to  the  last  evolution  of  ASEP 
included in R41.05 series of amendments as a positive advancement to better represent the 
actual motorcycle driving conditions. 

1.2.7. Question  No.  7  -  Which  of  the  following  changes  on  ASEP 
procedure  do  you  think  that  would  result  in  a  more 
comprehensive  evaluation  of  the  sound  emission  for  the 
concerned vehicle categories? 

Options: Yes, partially, no, I don’t know 

26 

 
Answers received as other 

Figure 8: Answers to question 7 

Engine  acceleration;  no  actions;  nothing  to  change;  all  gears;  combination  of  mentioned 
factors; including more measurement points. 

Additional comments 

“Both test speed and engine speed are relevant and must reflect real world driving conditions. 
Increasing  the  number  of  additional  operating  conditions,  including  random  measurement 
points and Including partial throttle opening tests would even better reflect real world driving 
conditions, but would possibly make the test procedures more complicated than they already 
are.” – FEMA 

“random points are very effective for checking the whole range of possible use cases” 

- 

Swiss Federal Roads Office (FEDRO) 

"Random is a burden for both manufacturer and TS when it comes to the inspection.Increasing 
the number of operating conditions could be better, but it's also well known that we couldn't 
test an infinite number of points." – UTAC CERAM 

“It is as simple as this: No operating condition should be left without a noise limit, i.e. we should 
introduce a general upper lid!” – Umweltbundesamt 

"Current  ASEP  procedure  (R41-04  series)  will  soon  be  replaced  by  the  R41-05  series  of 
amendments (adopted at GRBP in September 2020) and as a result: 

The range of test speeds will be extended; 

And the range of test engine speeds will be extended; 

And the number of additional operating conditions to be tested will be increased And partial 
throttle opening tests will be included. 

Random measurement ('mystery') points were already included under R41-04. The number of 
random measurement points will be substantially increased under R41-05 (compared to R41-
04)." – ACEM 

 
 
 
“We believe it is not necessary to take any further changes in ASEP.” – MV Agusta SpA 

“Those items are included in R41-05. It is not necessary to take any further measures at this 
moment.” – Yamaha Motor Co., Ltd. 

"With the upcoming R41-05 series of amendments (adopted at GRBP in September 2020) the 
range of test speeds and the range of test engine speeds will be extended; The  number of 
additional operating conditions to be tested will be increased and partial throttle opening tests 
will be included. 

Number of random measurement points will be increased under R41-05 (compared to R41-
04). 

The test will be possible also on 1st gear" – Ducati Motor Holding 

“A wider band of engine speeds and vehicle speeds would be more representative of real world 
use although expected changes to regulations from the 05 series of amendments will tackle 
some of these issues.” – FIM 

“All  these  aspects  are  covered  by  UNECE  R41-05  series  of  amendment.  Which  is  not  yet 
referenced by EU type approval regulation.” – KTM AG 

“Answering this question will depend on the point of view: because the recently adopted ASEP 
2.0 (R41/05) has all the items proposed under question 7 are already included, if you compare 
it with R41/04.” – Honda 

“All the listed items are inside the document "ECE/TRANS/WP.29/GRBP/2020/9 - (IWG ASEP) 
Proposal for a new 05 series of amendments to UN Regulation No. 41 (Noise emissions of 
motorcycles)". In the future the Limit curve for cruising and partial load has to be lower than 
the wot-ASEP-limit-curve.” - Ministry of Transport and digital Infrastructure of Germany (BMVI) 

“Avoid manufacturer to be  prepared for  test  scenario and apply  any  strategies. - TÜV  SÜD 
Czech s.r.o. 

“It is a combination of the mentioned factors which makes it possible to test under many more 
driving conditions than before. 

Ministry  of  ecological  transition  Test  speeds  and  engine  speeds  already  have  an  extended 
range. - RDW 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles. - Ministry of transport and Construction of the Slovak republic 

“Engine  speed  dominates  engine  noise  and  exhaust  noise. We  can  expect  that  it  will  have 
more effect on vehicle noise than vehicle speed in itself - IDIADA 

"Current  04  series  will  soon  be  replaced  by  the  R41-05  series  of  amendments  (adopted  at 
GRBP in September 2020) and as a result: 

the range of test speeds will be extended; 

and the range of test engine speeds will be extended; 

And the number of additional operating conditions to be tested will be increased And partial 
throttle opening tests will be included. 

Random measurement points were already included under R41-04. 

Number of random measurement points increased under R41-05 (compared to R41- 04)." - 
IMMA 

“The points noted above will be covered by the move to ASEP2” - Triumph Motorcycles 

“The selected answers are all included in the new R41-5 ASEP procedure.” - 

Kawasaki Motors Europe N.V. 

28 

 
“Maybe this could have more information for ASEP in other conditions that WOT, the rest of 
the parameters are OK for us RPM or speed of the test.” - LCOE 

Conclusions 

For this topic there isn’t a factor prevailing over the other. The balanced answer’s percentage 
between all the proposed changes on ASEP procedure indicates that stakeholders don’t see 
a specific weak point on the existing ASEP test procedures. 

1.2.8. Question No 8 - Do you think that the tampering (e.g. fitting of 
non-  approved  exhaust  systems)  on  L-category  vehicles 
resulting in an increase of their sound emission levels makes 
a negative social perception of such vehicles? 

Options: Yes, no, I don’t know 

Additional comments 

Figure 9: Answers to question 8. 

“Noise  nuisance  due  to  modifications  to  exhaust  silencers  is  significant  and  very  poorly 
controlled by law enforcement.” – UTAC CERAM 

“Tampering with exhaust systems is one of the main causes of noise annoyance by mopeds, 
motorcycles, trikes and quads.” – FEMA 

"Absolutely! This the most important point. In my opinion the very first buy after the bike is an 
aftermarket exhaust which is - surprising - by far more noisy. 

I strongly think that real limitation of the tampering and real replacement exhaust homologation 
could be enough to kill noise pollution. Please, everybody knows that the most annoying and 
disturbing bikes are driven without any catalyst device and with replacement exhaust muffler. 
If nobody knows this at the European Commission it becomes urgent they go in the real world, 
on road. 

Down the R41 limit or 168/213 limit or reinforcement of ASEP have no impact on the above 
modified bikes. Definitively." – UTAC CERAM 

“We  do  experience  complaints  from  the  public  regarding  tampered  L-category  vehicles.”  - 
Norwegian Public Roads Administration 

“A suggestive question, the answer is obvious, I believe.” - Umweltbundesamt 

 
 
 
 “Tampered, noisy vehicles (e.g. fitting of non-approved exhaust systems, having inserts/dB-
killers  removed  from  approved  exhaust  systems,  ...)  are  noted  more  than  non-tampered 
vehicles and increase therefore the negative perception of the motorcycle fleet.” – ACEM 

“The tampering  of the  exhaust  systems  is  the  main source  of  increase in the  noise level  of 
motorcycles.” – MV Agusta Motor SpA 

“It  is  considered  as  the  most  contributing  factor  to  traffic  noise  that  is  perceived  as  noise 
pollution.” – Yamaha Motor Co., Ltd. 

“Tampered  noisy  vehicles  (e.g.  fitting  of  non-approved  exhaust  systems,  having  inserts/dB-
killers  removed  from  approved  exhaust  systems,  ...)  are  noted  more  than  non-tampered 
vehicles and increase therefore the negative perception of the motorcycle fleet.” – Ducati Motor 
Holding 

“This is by far and away the largest cause of complaints.” – FIM 

“Tampered vehicles (e.g. fitting of non-approved exhaust systems, having inserts/dB- killers 
removed from approved exhaust systems, ...) are often emitting higher noise emission levels 
than  the  original  vehicle,  and  are  noted  more  than  non-tampered  vehicles  and  increase 
therefore the negative perception of the motorcycle fleet.” – KTM AG 

“Non approved silencers have no limits to comply to. They can be as loud as they want. People 
with no knowledge of or interest in motorcycles are unable to differentiate such 'single event' 
noise  cases  with  non-approved  mufflers  from  OEM  spec  motorcycles  and  may  wrongfully 
generalize as 'all motorcycles are loud'”. – 

Honda 

“Tampering  (mechanical  or  steering  of  flap  systems)  of  OEM  vehicles  are  the  two  big 
Problems.  Additional  the  replace  silencers  which  buildt  around  the  test  situation  of  the 
Regulation 41 (e.g.by the brands Kesstech or Jeckil and Hyde) with their modes of complet 
open flaps are the biggest Problems, which gives a negative Image to motorcycles. Also some 
modes of vehicle manufactures acts like manipulation outside the test situations (e.g. partial 
load etc.).” - Ministry of Transport and digital Infrastructure of Germany (BMVI) 

“Excessive sound emissions are the main bases of annoyance. The excesses will mostly come 
from older vehicles and/or tampered vehicles.” - RDW 

“Loud pipes do not save lives, but loud pipes make noise” - Individual 

“In some countries, the social perception of L-vehicles is quite negative between the general 
public.  These  vehicles  are  associated  with  noise,  indiscipline  and  dangerous  driving 
behaviour.” – IDIADA 

“Tampered  noisy  vehicles  (e.g.  fitting  of  non-approved  exhaust  systems,  having  inserts/dB-
killers  removed  from  approved  exhaust  systems,  ...)  are  noted  more  than  non-tampered 
vehicles and increase therefore the negative perception of the motorcycle fleet.” - IMMA 

“This is the clear example that makes that people have the association of the sound emissions 
loud to the motorbikes. If there is just 1 non-approved exhaust very noise has a big impact in 
a road that can circulate a lot of motorbike during a day for 1 noisy motorbike the impact is 
very high to the global noise of the rest of the motorbikes and the rest of the vehicles.” - LCOE 

Conclusions 

There  is  unanimity  on  this  question.  Tampered  vehicles  make  a  big  damage  on  the  social 
perception of motorcycles as source of disturbing noise. 

30 

 
1.2.9. Question No 9 - According to your point of view, which of the 
following vehicle categories are more likely to be tampered in 
a way that increases their sound emission level? 

Options: L3e-A1 (light motorcycles), L3e-A2 (medium motorcycles), L3e-A3 (high performance 
motorcycles), L5e (tricycles), L6e (light quadricycles), L7e (heavy quadricycles) 

Additional comments 

Figure 10: Answers to question 9. 

“We  cannot  answer  Q9,  because  it  is  not  a  matter  of  light  or  heavy  motorcycles  and  other 
vehicles or the displacement of their engines. It is the type of the vehicle (e.g. sports bikes, 
custom bikes etc.) and how they are used.” – FEMA 

“market distribution in Switzerland contains relatively few tricycles and quadricycles” 

- 

Swiss Federal Roads Office (FEDRO) 

"My point of view is based on what I see on the road. 

In addition, a quick check in a replacement exhaust manufacturer shop could easily convince 
anybody about the most tampered motorcycles." – UTAC CERAM 

“Tampering  is  not  the key  problem  but  occurs  across  the  board.  Problematic  are  the  many 
vehicles which are noisy by design right from the production line.” - Umweltbundesamt 

“It is hard to rank them because it depends on the kind of vehicle, and it can differ even within 
the same vehicle sub-category. Rather than on L-category categorisation, ranking is related to 
usage characteristics (e.g. Leisure vs. Commuting), vehicle price and vehicle power, peculiar 
to each sub-category.” – ACEM 

“We don't have enough information to give a rank.” – MV Agusta SpA 

 “We do not know about L6e or L7e. For other sub-categories, it is hard to rank them because 
it depends on vehicle type even within the same sub-category. Our ranking is based on hobby 
characteristics peculiar to each sub-category.” – Yamaha Motor Co., ltd. 

"It is hard to rank them because it depends on vehicle type even within the same sub- category. 
We do not know about L5e, L6e and L7e." - Ducati Motor Holding 

“Fashion and vehicle style are a better indicator of propensity to tamper than type approval 
category.” – FIM 

 
 
 
“A ranking based on vehicle categories is not possible. Even within the same sub- category 
there may be variations related to various factors, like the usage characteristics (i.e. leisure, 
commuting) as well as the vehicle price.” – KTM AG 

“In general, more expensive vehicles tend to be more equipped with aftermarket exhausts” – 
Honda 

“Most of L-cat-vehicles (Sport bikes and choppers) are L3e-A3 in Germany. For their owners 
Sound seems to be important. Young Drivers of L3e-A1 act in the same way. L7e vehicles are 
very  often  used  tampered  in Germany.  L5e  and L6e are quite seldom  manipulated  on  their 
silencers in Germany.” - Ministry of Transport and digital Infrastructure of Germany (BMVI) 

"This is combination of leisure use and the amount of registered vehicles. 

The  L3e-A3  are  in  practice  the  big  twin-engine  cruisers  on  which  the  exhaust  mufflers  and 
catalytic converters are replaced by ‘open’ pipes. This also applies to the sport bikes, naked 
bikes, streetfighters and moto-cross bikes. 

The L3e-A2 are in practice modified to have extra power, which leads to extra sound. The L7e 
are in practice the Quads with “CVT” and ex-off-road Quads with power limiters (15kW), which 
are individual approved in other countries and then brought to NL (99/37) and afterwards being 
modified to increase the power. 

The L5e are in practice the “Trikes” on which the exhaust mufflers and catalytic converters are 
replaced by ‘open’ pipes."” - RDW 

“The lower the dynamic performance, the more the user will want to make noise.” - 

Ministry of ecological transition 

“It is hard to rank them because it depends on vehicle type even within the same sub- category. 
Rather than on L-category, ranking is related to usage characteristics peculiar to each sub-
category (e.g. Leisure vs. Commuting), vehicle price and vehicle power.” - IMMA 

“We don't have any specific data on this but assume tampering is related to the user and not 
the vehicle category.” - Kawasaki Motors Europe N.V. 

“This ranking is for all approved vehicles and components.” - LCOE 

 Conclusions 

The main trends detected when analyzing the received answers are: 

-Two-wheelers  are  understood  as  being  likely  to  be  modified,  and  among  them  high- 
performance motorbikes get the biggest percentage of answers 

-Tricycles and heavy quadricycles don’t seem to create big concerns regarding its possibility 
to be modified. 

-Light  quadricycles  are  the  sub-category  perceived  as  having  the  lower  potential  of 
modification. 

32 

 
 
 
1.2.10. Question  No  10  -  According  to  your  perception,  are 
motorcycles,  tricycles  and  quadricycles  more  likely  to  be 
driven  in  an  aggressive  way  than  other  categories  of 
vehicles? 

Options: Yes, no, I don’t know 

Additional comments 

Figure 11: Answers to question 10. 

“Due to the high power/weight ratio of L-category vehicles often accelerate quicker than other 
vehicles. Some people might see this as aggressive driving. The same goes for the agility of 
motorcycles when riders make use of it to filter through traffic jams or slow driving traffic. etc. 
This might also be seen as aggressive driving. In fact, most riders are very well aware of their 
vulnerability and ride accordingly.” – FEMA 

"Motorcycle - more aggressive driving” – Anonymous 

“The means of mobility do not correlate to driver/rider behavior. A person who pushes the limit 
of a vehicle is not tied to a single type of vehicle.” – Polaris Inc. 

"What a huge bias in the question! 

If I do compare M1 and L3e-A3 my reply is obviously ""yes"". If I do compare M1 and L6e-B 
my reply is obviously ""no"". 

Please, consider a separate question for each category and I will provide you with relevant 
replies." – UTAC CERAM 

“More likely than trucks, but just as likely as sports cars. – Umweltbundesamt 

 "ACEM is not aware of any data about this. 

Policy making should not be based on perceptions. 

Aggressive driving is the driver/rider behaviour, independent of vehicle type. Any vehicle can 
be driven aggressively and annoy other people." – ACEM 

“We don't have evidence or data to give an objective answer.” – MV Agusta Motor SpA 

"We do not have data on this. Perceptions should not be the basis of legislation." – 

 
 
 
 
Yamaha Motor Co., Ltd. 

"Aggressive driving is related to the driver/rider behaviour, independent of vehicle type. I'm not 
aware of any data about this" – Ducati Motor Holding 

“Car club culture has been linked to aggressive driving and excessive noise. It as also worth 
noting that "aggressive riding" is contextual and riders filtering or using too low a gear may be 
perceived as being aggressive but in actual fact behaving legally and rationally.” – FIM 

"Almost every type of vehicle can be used inappropriately. We are not aware about any specific 
studies about aggressive driving. We do not support aggressive driving at all on public roads." 
– KTM AG 

“Aggressive driving is the driver/rider behaviour, independent of vehicle type. Any vehicle can 
be driven aggressively and annoy other people.”- Honda 

“Because these vehicles are leisure time vehicles which have to produce fun for the driver.” - 
Ministry of Transport and digital Infrastructure of Germany (BMVI) 

"The ratio of daily use vehicles compared to leisure use vehicles, in combination with a higher 
Power  to  Mass  Ratio,  is  higher  with  these  vehicle  categories than  other vehicle  categories. 
Therefor the risk of a more aggressive driving style is higher. 

It should however be remarked that young motorcycle drivers are limited by the driver license 
regulations (Directive 2006/126/EG, A1 18 years, A2 20 years and A 22 years)." - RDW 

Yes for motorcycles - Ministry of ecological transition 

"IMMA is not aware of any data about this. 

Policy making should not be based on perceptions. 

Aggressive driving is the driver/rider behavior, independent of vehicle type. Any vehicle can be 
driven aggressively and annoy other people" - IMMA 

“We don't have any specific data on this but assume aggressive riding is related to the user 
and not the vehicle category.” - Kawasaki Motors Europe N.V. 

Conclusions 

For  this  topic  there  is  a  44  %  of  affirmative  answers  against  a  28  %  of  negative  answers. 
Among  stakeholder’s  remarks  we  find  from  one  side  opinions  indicating  that  due  to  the 
favorable power to mass ratio some L-category vehicles have a performance level that can be 
perceived  as  aggressive  driving,  and  from  the  other  side,  those  vehicles  may  tend  to  be 
aggressively driven but in the same way as for other kind of vehicles, because the driver is the 
final responsible of how a vehicle is driven. 

34 

 
 
 
1.2.11. Question  No  11  -  In  your  opinion,  what  is  the  effect  of  an 
aggressive driving style on the noise pollution created by L-
category vehicles in urban and extra-urban environments? 

Options:  

Urban environment: Null, low, medium, high  

Extra-urban environment: Null, low, medium, high 

Figure 12: Answers to question 11 for urban environment. 

Figure 13: Answers to question 11 for extra-urban environment. 

Additional comments 

“Again, it depends on what is meant by aggressive driving style. Extreme fast acceleration with 
high RPM and riding with high RPM in general add to noise annoyance and could be seen as 
an aggressive driving style.” – FEMA 

"Same  as  10.,  how  can  I  consider  both  L3e-A3  and  L6e-B  in  the  same  reply?  Aggressive 
driving has a noise impact only in urban environment." – UTAC CERAM 

 
 
 
 
 
 
“Just look at the available data!” – Umweltbundesamt 

"Aggressive riding, if resulting in high rev’ing of the engine, may lead to noise pollution. 

Single noise events (e.g. caused by aggressive driving) are remarked as a major contributor 
to people annoyance. 

Medium was chosen for extra urban because of an extrapolation between following two extra-
urban cases was considered: 

Extra-urban (rural): High 

Extra-urban (highway): Low" – ACEM 

“Aggressive driving, understood as an increase in engine revs, can contribute to increasing 
disturbance to people, especially in urban areas.” - MV Agusta Motor S.p.A. 

"We do not have data on this. Perceptions should not be the basis of legislation." – 

Yamaha Motor Co., ltd. 

"Aggressive riding, if resulting in high revving of the engine, may lead to extra noise pollution. 

Single noise events (e.g. by aggressive driving) are remarked as a major contributor to people 
annoyance, in particular in urban areas. 

Extra-urban environment: 

Medium chosen as balance b/w high on Extra-urban (rural) and Low on Extra-urban (highway) 
environments." – Ducati Motor Holding 

“Not  all  so-called  aggressive  driving  is  genuinely  aggressive,  although  it  clearly  has  some 
impact. A bigger impact is the prevalence of illegal or tampered exhausts.” – FIM 

"Aggressive riding, if resulting in high revving of the engine, may lead to extra noise pollution 

Single noise events (e.g. by aggressive driving) are remarked as a major contributor to people 
annoyance. Especially in urban and populated rural environment. 

Medium was chosen for extra urban because: Extra-urban (rural): High 

Extra-urban (highway): Low" – KTM AG 

“Single noise events (e.g. by aggressive driving) are remarked as a major contributor to people 
annoyance.” – Honda 

“High  load  or  rpm  produces  independently  from  the  area  high  Sound  Pressure  Levels.”  - 
Ministry of Transport and digital Infrastructure of Germany (BMVI) 

“An  aggressive  driving  style  is  negatively  affecting  the  sound  emissions  of  L-category 
vehicles.” - RDW 

“L-type vehicles are driven in a sportive way, even in urban environments. This implies high 
vehicle  acceleration  and  deceleration  combined  with  sudden  changes  in  engine  rpm.  This 
produces  noise  transients  that  tend  to  be  more  annoying  than  constant  steady  state  noise 
levels” - IDIADA 

"Aggressive riding, if resulting in high engine revolutions, may lead to extra noise pollution 

Single noise events (e.g. by aggressive driving) are remarked as a major contributor to people 
annoyance. 

Medium was chosen for extra urban because Extra-urban (rural): High 

Extra-urban (highway): Low" - IMMA 

Conclusions 

36 

 
It  seems  that  the  perception  of  the  high  effect  of  an  aggressive  driving  style  on  the  noise 
pollution created by L-category vehicles in urban environment (88 %) is higher than in extra-
urban environment (41 %), but in both cases the added percentage of answers for “low” and 
“null” is small (6 % and 22 % respectively). 

1.2.12. Question  No  12  -  European  Union  cities  are  progressively 
reducing  the  access  and  maximum  speeds  on  congested 
traffic  areas  based  in  pollutants  emissions  criteria.  Do  you 
think that this policy contributes also to limit the access to the 
clean  air  zones  to  motorcycles,  tricycles  and  quadricycles 
having a high level of sound emissions? 

Options: Yes, partially, no, I don’t know  

Figure 14: Answers to question 12. 

Additional comments 

“Unfortunately, new vehicles that comply with clean air criteria are still as modifiable as ever.” 
– UTAC CERAM 

“One just cannot speak of vehicles with a high level of sound emission because 1. it depends 
on how one defines this (some authorities use the static sound emission as a criterium, which 
doesn't  mean  anything  at  all)  ,  2.  the  level  of  sound  emission  mainly  depends  on  how  the 
vehicle is driven and 3. the question if a vehicle is still conform type -approval (not tampered 
with).” – FEMA 

“We find the question unclear.” - Norwegian Public Roads Administration 

“Partially, but modern clean bikes are by no means automatically less noisy when pushed hard 
by their driver (see regulatory deficits above).” - Umweltbundesamt 

“More noise is generated when speeding the engine (albeit at low speeds) than at constant 
speeds” – Applus+ 

"Such  policies  usually  do  not  discriminate  on  the  basis  of  high  levels  of  sound  emission.  If 
access to city centers are forbidden to L-cat. vehicles, their scope include all types of L-cat. 
vehicles. Reduction in exhaust emissions would not always directly lead to reduction in sound 
emissions." – ACEM 

“We  do  not  see  relations  between  polluting  emissions  and  noise  emissions.”  –  MV  Agusta 
Motor SpA 

 
 
 
 
“Reduction  in  exhaust  emissions  would  not  always  directly  lead  to  reduction  in  sound 
emissions.” – Yamaha Motor Co., Ltd. 

"There is no relation between pollution and noise emission. Reduction in exhaust emissions 
would not always directly lead to reduction in sound emissions." – Ducati Motor Holding 

“These restrictions are based on type-approval characteristics rather than whether the vehicle 
has been tampered.” – FIM 

"Such  policies  usually  do  not  discriminate  on  the  basis  of  high  levels  of  sound  emission.  If 
access  to city  centres are forbidden  to  L-cat  vehicles,  their scope includes  all  type  of  L-cat 
vehicles. 

Looking at ICE vehicles, we do not see a clear relationship between the reduction in exhaust 
emissions and reduction in sound emissions." – KTM AG 

“Pollutant emissions as the only criterion for traffic restrictions, banning L-cat based on noise 
will  not  change  much  on  overall  noise.  There  is  no  link  between  the  vehicle's  pollutant 
emissions and the sound it makes.” – Honda 

“In the future it will be the same discussion like passengers cars diesel (NOx/PN) “. 

Ministry of Transport and digital Infrastructure of Gemrany (BMVI) 

“The driving style is an important factor in sound emissions. Also with lower speeds you can 
create a high level of sound emissions, especially vehicles with high PMR’s and higher engine 
capacities.” – RDW 

“The level of depollution of vehicles does not prejudge the level of noise emissions.” 

- 

Ministry of ecological transition 

“Class L-driver are the smallest amount of the traffic. Sound and emissions criteria should be 
not mixed regarding clean air zones.” Anonymous 

"Such  policies  usually  do  not  discriminate  on  the  basis  of  high  levels  of  sound  emission.  If 
access  to city  centres are forbidden  to  L-cat  vehicles,  their scope includes  all  type  of  L-cat 
vehicles. 

Reduction  in  exhaust  emissions  would  not  always  directly  lead  to  reduction  in  sound 
emissions." - IMMA 

Conclusions 

Stakeholder’s  opinions  show  that  half  of  them  understand  that  reducing  the  access  and 
maximum  speeds  on  congested  traffic  areas  has  a  partial  impact  on  limiting  the  number  of 
noisy L-category vehicles in these areas, and that almost a third of them (29 %) think that these 
restricted areas contribute to limit the access to the clean air zones to motorcycles, tricycles 
and quadricycles having a high level of sound emissions. 

1.2.13. Question No 13 - Electric L-category vehicles are increasing 
their presence on streets and roads. Which percentage of EV 
do you estimate to find in your country fleet in the future for 
the indicated vehicle categories and timelines? 

Options: For motorcycles, tricycles and quadricycles: 

In 5 years 10 % / 30 % / 50 % / 70 % / 90 % / Other 

In 10 years 10 % / 30 % / 50 % / 70 % / 90 % / Other 

38 

 
Figure 15: Answers to question 13. 

Additional comments 

"Electric vehicles are still very expensive for consumers and less funny for users. On the other 
hand, certain manufacturers will not have the choice of switching to electric vehicles." – UTAC 
CERAM 

“In  2020  the  sales  of  new  electric  motorcycles  are  less  than  2  %  of  the  total  sales  of  new 
motorcycles  (source:  ACEM).  Also,  motorcycles  have  a  much  longer  lifespan  than  other 
vehicles. In the Netherlands, 34 % of the mc fleet is older than 25 year (source: CBS). Given 
these two parameters it is very unlikely that in 5 or 10 years the mc fleet will consist of more 
than 1 or 2 %.” – FEMA 

“not  sure  if  the  spreading  of  electric  motorcycles  will  be  successful  due  to  high  prices  and 
limited range (batteries)” - Swiss Federal Roads Office (FEDRO) 

 "Motorcycles:  probably  the  most  engine-related  vehicle  category  with  the  most  variety  of 
engine. Electric engine could not offer more fun than already provided by thermal engine. That 
become true for M1, but I don't think so for L3e. 

Tricycles: most of them are used for commute travels and are not well known for providing lot 
of fun. Electric will probably raise its rate. 

Quadricycles: most of them are purely dedicated to vocational purpose. Electric will become 
the  main  part  for  rational  considerations  (tco,  high-availability,  etc.)  and  urban  travels 
possibilities." – UTAC CERAM 

“We  particularly  believe  that  the  sale  of  moped  EVs  will  increase,  and  more  so  than 
motorcycles.” - Norwegian Public Roads Administration 

“I don't see any relevant trend to e-mobility for L-category vehicles besides scooters. 

And the fleet is generally replaced very slowly.” – Umweltbundesamt “We do not have data to 
make an estimate.” – MV Agusta Motors SpA “It is difficult to predict.” – Yamaha Motor Co., 
Ltd. 

“I have no information, so it is not possible to predict” – Ducati Motor Holding 

“Access  to  incentives  and  infrastructure  are  barriers  to  market  for  consumers.  We  would 
anticipate  this  being  removed  or  simplified  in  the  coming  years  to  increase  market  share 
rapidly. However, there is still and will be a large number of petrol engine vehicles on the road 
for many years due to the age of the current fleet. Even with expected bans on the sale of ICE 

 
 
 
 
vehicles,  petrol  engine  motorcycles  will  still  number  in  the  millions  across  the  EU  for  some 
decades to come.” – FIM 

“Difficult to estimate the uptake of EV's” – Honda 

“Changing will be lower than M1” - Ministry of Transport and digital Infrastructure of Germany 
(BMVI) 

“All low, because the vehicles are mostly leisure vehicles.” - RDW 

“European  motorcyclists  are  predominantly  hobby  riders  and  they  are  very  conservative.”  - 
Individual 

“It's clear that EV will increase but it's difficult to know right now.” - LCOE 

Conclusions 

The general perception is that EV fleet growing will be slow and progressive. Most remarks 
refer to the difficulty to make a forecast, and some of them name as factors slowing the growth 
of EV market share the high lifespan of L-category vehicles, the fact that they are mostly leisure 
vehicles, the price of these vehicles and their range limitations. The only category of vehicles 
where stakeholders see a potential significant growth of EVs is quadricycles. 

1.2.14. Question  No  14  -  Which  impact  do  you  think  that  a  future 
increasing percentage of electric L-category vehicles among 
your  country’s  fleet  would  produce  on  the  perceived  noise 
pollution? 

Options:  For  urban  environment  and  extra-urban  environment:  Negative  impact,  no 
improvement, low improvement, medium improvement, high improvement, I don’t know 

Figure 16: Answers to question 14 for urban environment 

40 

 
 
Additional comments 

Figure 17: Answers to question 14 for extra-urban environment 

"In the city, at low speeds, electric vehicles are very quiet. The impact will be great. Compared 
to today, electric vehicles in extra-urban conditions will also be less polluting." – UTAC CERAM 

"Answer depends on how you read the question 

Urban: Less tailgate sound emission, but below 25 km/h EV must make an artificial sound to 
warn pedestrians 

Extra-urban: Less tailgate sound emission, but with electric motorcycles, the drive- train also 
causes sound, which can be quite high (e.g. Harley-Davidson Lifewire). 

However: when the question refers to the current motorcycle park: EVs are in general quieter 
than combustion engines, which means that combustion engine vehicles will stick out more in 
future and be perceived as louder. In fact, this is already happening." 

– FEMA 

"No idling, no revs at the stop lane, very low cruising and wide open throttle noise. Electric L 
vehicles perfectly fit to cities when we consider the sound level. 

No impact out of urban environment." – UTAC CERAM 

“But only once the electric vehicles dominate the fleet.” – Umweltbundesamt 

“Since we cannot estimate the increase in electric vehicles in circulation, we cannot express 
an opinion on this point.” – MV Agusta Motors SpA 

“Generally, sound levels emitted from EVs appear to become lower when compared to engine-
driven  vehicles.  However,  sound  emission  levels  of  engine-driven  L-cat  vehicles  do  not 
contribute  to the  noise pollution  as  long  as they  are  operated  in an  appropriate  manner.”  – 
Yamaha Motor Co., Ltd. 

"Generally, sound levels emitted from EVs appear to become lower when compared to ICE 
vehicles. 

However, we have to take into account that sound emission levels of ICE OEM vehicles do not 
contribute  to the  noise pollution  as  long  as  they are  operated  in an  appropriate manner."  – 
Ducati Motor Holding 

 
 
 
“Noise pollution is primarily a peak event caused by illegal or tampered exhausts. Although 
electric motorcycles are evidently quieter than petrol motorcycles, the overall drop in constant 
noise  will  be  small.  This  will  serve  to  make  tampered  petrol  motorcycles  seem  louder  by 
comparison.” – FIM 

“Question is unclear. Who is addressed by the term "perceived"? The perceived noise pollution 
is highly subjective.” – KTM AG 

“Today's OEM spec vehicle ridden in a respectable manner are not causing annoyance. Even 
with increased EV's on the roads, as long as single noise events remain (from excessive speed 
or  rpm's  or  the  use  of  an  aftermarket  exhaust),  these  will  dictate  the  motorcycle  noise 
perception.” – Honda 

“Because of the very low tyre rolling noise the L category vehicles are more or less without 
Sound. This will give them a positive Image.” - Ministry of Transport and digital Infrastructure 
of Germany (BMVI) 

“EVs will be mostly used as urban personal transporters or goods delivery.” - TÜV SÜD Czech 
s.r.o. 

“The excessive sound emissions are the ones that are found annoying. Electric vehicles will 
not help in this matter. This can only help when combustion engines are banned. - Ministry of 
ecological transition 

It  can  locally  improve  the  noise  pollution  if  there  are  strict  requirements  of  fleet  renewal.”  - 
RDW 

“Regardless of the quiet EV's there would still be a focus on the low volume of "noisy" bikes.” 
- Triumph Motorcycles 

Conclusions 

Impact of a future percental increasing of electric L-category vehicles fleet on the perceived 
noise pollution is expected to be much higher in urban environment, where 56 % of answers 
indicate high improvement, than on extra-urban environment, where 45 % of answers indicate 
low improvement. 

42 

 
 
 
1.2.15. Question No 15  -  Please  indicate  which  in  your  opinion 
are  the  main sound emissions sources found on the following 
types of vehicles: 

Options: For L3e, L5e, PI L6e, CI L6e, L7e: Engine, tires, exhaust system, intake, transmission, 
otherIn 10 years 10 % / 30 % / 50 % / 70 % / 90 % / Other 

Additional comments 

Figure 18: Answers to question 15. 

“In  fact,  to  know  which  parts  make  the  loudest  sound  needs  expertise  knowledge  and 
appropriate devices to measure.” – FEMA 

“As  soon  as  vehicle  has  bodywork  length  of  fairing  sound  level  could  be  lowered  and  the 
exhaust muffler is no more the main emitter.” – UTAC CERAM 

“We can only express an opinion on vehicles of category L3e which are our production.” – MV 
Agusta SpA 

"We do not know about L6e or L7e. 

For other L-cat vehicles, it is difficult to give collective description of the noise source since it 
is different by vehicle type. Sound reduction strategies are already incorporated not only into 
exhaust systems but various components of our vehicles." 

– Yamaha Motor Co., Ltd. 

"The noise source is highly vehicle model dependent. 

In general,  it  can  be  said that for  L3e  vehicles: Exhaust,  engine, Intake, Transmission  (and 
tyres if M+S) are the main sources." – Ducati Motor Holding 

“Whilst other sources of noise can be significant, exhaust noise is by far and away the loudest 
on almost all models.” – FIM 

“The overall noise of the vehicle is a combination of sources. Due to less space, 2- wheeled 
vehicles may  have more  challenges to fit  a  large  exhaust.  3-wheeler  and  4-  wheelers  have 

 
 
 
 
more  car-like  tyres  (or  even  tyres  with  off-road  profile),  for  these  vehicles  the  tyre  noise 
component is larger than for the 2-wheeled vehicles” - Honda 

"The tyres of L3e produces only a Minimum of the tyre rolling Sound of the tyres of cars (also 
L5e, L6e and L7e tyres). Transmission of motorbikes is only a Problem if it is not belt or cardan-
driven. Air Intake of covered vehicles (L6e and L7e) is not a Problem." - Ministry of Transport 
and digital Infrastructure of Germany (BMVI) 

“Exhaust system and intake system for all vehicles, except CI L6e (only engine). 

These are the items that are currently mostly modified during in-use.” - RDW 

"The noise source is highly vehicle model dependent. In general, It can be said that 

- 

- 

for unbodied vehicles (such as L3e): Exhaust/Engine, Intake, Transmission, Tyres 

for bodied vehicles: Exhaust, Intake, Tyres, Transmission/engine 

It is difficult to give collective description of the noise source since it is different by vehicle type. 
Sound reduction strategies are already incorporated not only into exhaust systems but various 
components of our vehicles. 

Due to less space, 2-wheeled vehicles may have more challenges to fit a large exhaust. 3-
wheeler and 4-wheelers have more car-like tyres (or even tyres with off- road profile), for these 
vehicles the tyre noise component is larger than for the 2- wheeled vehicles” - IMMA 

“Noise source ranking is model specific, so it’s difficult to answer.” - Kawasaki Motors Europe 
N.V. 

Conclusions 

Stakeholder’s  answers  indicate  that  exhaust  system  and  engine  are  the  most  significant 
perceived sources of sound, but the results show also that for each vehicle category the weight 
of  some  factors  varies  due  to  their  specifications.  For  example,  for  four  wheelers,  and  in 
particular the off-road ones, tyre noise is understood as a more significant sound source, and 
for  compression  ignition  L6e  quadricycles  engine  noise  is  identified  as  a  relevant  sound 
source. 

44 

 
 
 
1.2.16. Question No 16 - In which of the following vehicle’s parts or 
systems do you think that it is more likely to find cost-effective 
solutions  in  order  to  reduce  the  sound  level  of  L-category 
vehicles? 

Options: Giving a mark from 0 (least likely) to 10 (most likely) to: Exhaust silencers, engine 
mapping,  transmission / gearing,  engine/gearbox  shielding,  intake  ducts and inlet  silencers, 
exhaust valve, tires, other 

Additional comments 

Figure 19: Answers to question 16. 

"With certain brands and types of motorcycles it is probably possible to reduce sound emission 
by developing better silencer and make not or different use of valves. Also engine mapping 
can be used. However, these measures come at the cost of performance in power and torque, 
which also can lead to a negative effect (less torques means the need of higher RPM). 

shielding of parts may help but is often in practice hardly possible. To develop quieter intake 
ducts and transmissions may have an effect with some brands and models, but the costs may 
be too high. 

Motorcycle tyres hardly add to the sound emission because of their different shape. 

It may have some effect with trikes and quads." – FEMA 

“En los vehículos L la principal fuente de ruido actualmente es el escape y en menor medida 
la  admisión.  Considero  que  reducir  las  emisiones  de  ruido  desde  el  punto  de  vista  de  los 
costes no supone ningún problema. El problema es que el mercado demanda motocicletas 
ruidosas.” – Ayuntamiento de Madrid 

“As  soon  as  vehicle  has  bodywork  length  of  fairing  sound  level  could  be  lowered  and  the 
exhaust muffler is no more the main emitter.” – UTAC CERAM 

“The  cost  effectiveness may  vary  between vehicle models  and  between manufacturers, cfr. 
our answer to Q.15.” – ACEM 

“The cost effectiveness varies depending on vehicle types.” – MV Agusta SpA 

 
 
 
 
“Cost effectiveness varies depending on vehicle types.” – Yamaha Motor Co. Ltd. 

“No answer because the cost effectiveness depending on vehicle category and vehicle types.” 
– Ducati Motor Holding 

“Whilst each improvement will have an effect on overall noise levels, customers will still seek 
to "nd workarounds and develop louder exhaust noise.” – FIM 

“Due to the variety of vehicle types within the L-category and their related architectures it is not 
possible to give a clear answer.” – KTM AG 

“There are no easy and low-cost solutions to bring down the L-cat noise further.” – 

Honda 

“Volume of silencers and steering of flap Systems are easiest modifications. Mapping, gearing 
engine/gearbox shielding are possible with low costs, but will be only accepted by the Driver if 
the driving style and/or the view of the vehicle is not influenced in a negative manor.” - Ministry 
of Transport and digital Infrastructure of Germany (BMVI) 

“It is possible to get the motorcycles very silent, then the motorcycles are probably perceived 
as a lot less fun.” - RDW 

"No Answer, the cost effectiveness may vary between vehicle type and manufacturers (see 
answer to Q15)" - IMMA 

"What is a ""cost effective"" solution? What level reduction?" - Triumph Motorcycles 

“Solutions will be model specific, so it’s difficult to answer.” - Kawasaki Motors Europe N.V. 

Conclusions 

Most  stakeholders  find  difficult  to  give  a  general  answer  to  this  question  because  of  the 
diversity  of  vehicle  specifications.  The  main  detected  trends  are  that  exhaust  systems  are 
understood as more likely to find cost-effective solutions in order to reduce the sound level of 
L-category vehicles and that tyres are considered as least likely to find cost-effective solutions 
in order to reduce the sound level of L-category vehicles. 

46 

 
 
 
1.2.17. Question  No  17  -  From  your  experience,  for  motorcycles, 
tricycles and quadricycles using absorbent fibrous materials 
in its exhaust silencers what is the significance of this feature 
for the improvement on vehicle’s  sound emission levels? 

Options: For motorcycles, tricycles and quadricycles: Null, low, medium, high 

Additional comments 

Figure 20: Answers to question 17 

"The longer the exhaust line is, the easier it is in my opinion to relax the exhaust gaz. On a 
quadricycle  it  is  easier  to  muffle  even  without  fibrous  materials,  unlike  motorbikes  and 
tricycles." – UTAC CERAM 

“We do not have the knowledge to answer this question.” – FEMA 

“No experience” – European Commission 

“I am not an expert in exhaust constructions” - Swiss Federal Roads Office (FEDRO) 

"To be honest I know vehicles which use fibrous materials, but I don't exactly the same version 
without  fibrous  materials.  I  cannot  compare  anything  and  give  a  judgement  about  fibrous 
materials efficiency." – UTAC CERAM 

“If it is used, the effectiveness is vehicle specific, varying from medium to high. For absorption 
exhaust silencers, the fibrous material is the essential element of the system.” – ACEM 

“The effectiveness is low in our actual exhaust silencers design.” – MV Agusta Motor SpA 

 “It is highly vehicle-type-dependent how much the exhaust system contributes to the whole 
sound emission level of the vehicle, and thus it is difficult to indicate collectively how effective 
fibrous  materials  are  in  improving  sound  emission. While  it  is  true  that  fibrous materials  do 
good for sound level reduction, they are already employed for many existing vehicle models. 
That  means,  if  this  question  is  about  how  far  it  is  possible  to  improve  the  current  sound 

 
 
 
 
emission  levels  through  use  of  such  materials,  then  we  will  have  to  say  we  cannot  expect 
further improvements.” – Yamaha Motor Co., Ltd. 

"Motorcycles: 

For absorption exhaust silencers the fibrous material is the essential element of the system. 

In my opinion there is no improvement on vehicle’s sound emission levels acting on the fibrous 
material. 

This material is already optimized." – Ducati Motor Holding 

“The age of the material reduces its effectiveness.” – FIM 

“If it is used, the effectiveness is vehicle specific, varying from medium to high. For absorption 
exhaust silencers, the fibrous material is the essential element of the system.” – KTM AG 

“Often it helps on new vehicles. The altering of this material is often negative.” - 

Ministry of Transport and digital Infrastructure of Germany (BMVI) 

“The Regulation should be design neutral and the durability tests should ensure that the tested 
exhaust systems are durable throughout the lifetime of the vehicles.” - RDW 

“Reflective exhaust systems are more stable than absorption (fibrous materials) ones. Ministry 
of transport and Construction of the Slovak republic Ministry of transport and construction of 
the Slovak republic have no experience in test and approving L- category vehicles.” - Ministry 
of transport and Construction of the Slovak republic 

“If  engine  noise  (combustion  and  mechanical)  is  very  high  the  contribution  of  the  exhaust 
system will be smaller and therefore the modifications in its design will be less noticeable.” - 
IDIADA 

“If it is used, the effectiveness is vehicle specific, varying from medium to high. For absorption 
exhaust silencers, the fibrous material is the essential element of the system.” - IMMA 

“Depends on exhaust design of each specific model.” Kawasaki Motors Europe N.V. 

 Conclusions 

Stakeholder’s opinions give a similar significance for the improvement of sound emission levels 
on  motorcycles,  tricycles  and  quadricycles  using  absorbent  fibrous  materials  in  its  exhaust 
silencers. The relevance of this feature tends to be understood as medium, but some remarks 
indicate that the particular vehicle’s specifications may have a great influence on how using 
absorbent fibrous materials in its exhaust silencers impacts on sound emissions. 

48 

 
 
 
1.2.18. Question No 18 - According to your experience, in which of 
the following categories absorbent fibrous materials are more 
commonly used to reduce sound levels? 

Options: Giving a mark from 0 (least commonly used) to 10 (most commonly used) to: L3e-A1 
(light  motorcycles),  L3e-A2  (medium  motorcycles),  L3e-A3  (high  performance motorcycles), 
L5e  (tricycles),  L3e-AxE  (enduro  motorcycles),  L3e-AxT  (trial  motorcycles),  L6e  (light 
quadricycles), L7e (heavy quadricycles) 

Additional comments 

Figure 21: Answers to question 18. 

“We do not have the expertise knowledge to answer this question.” – FEMA 

“No experience” – European Commission 

“I am not an expert in exhaust constructions” - Swiss Federal Roads Office (FEDRO) 

“I do not have a relevant point of view of the whole market, sorry.” - UTAC CERAM 

"Fibrous materials are not much used for our L3e vehicle models. 

We do not have homologated vehicles in other categories." - MV Agusta Motor S.p.A. 

“Fibrous materials are already used for our existing vehicle models.” - Yamaha Motor Co., Ltd. 

“Also NORESS use fibrous material in a large way.” - Ducati Motor Holding 

“The FIM does not manufacture motorcycles.” - Federation Internationale de Motocyclisme 

"Fibrous  materials  used  in  vehicles  with  less  space  for  exhaust,  but  also  the  cost  of  this 
technology needs to be considered. 

We don't have any L5e, L6e, L7e Type approved models in EU." – Honda 

“The  cost  of  the  exhaust  system  is  much  depending  on  the  material  choices.  After  market 
systems often make use of cheaper materials in order to produce cheaper systems. Overall 
the  low  end  (cheaper)  models  of  all  categories  are  expected  to  be  affected  by  the  use  of 
cheaper materials. High end (more expensive) models of all categories are expected to be less 
effected by the use of cheaper materials since they will make use of more durable and more 
expensive materials.” - RDW 

 
 
 
 
“Fibrous materials are principally used for L3 vehicles, but only constructors could say in which 
proportions.” - Ministry of ecological transition 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles.” - Ministry of transport and Construction of the Slovak republic 

"No IMMA reply, each individual OEM to reply" IMMA 

“Depends on exhaust design of each specific model.” - Kawasaki Motors Europe N.V. 

Conclusions 

The  results  overview  shows  that  stakeholders  reckon  that  absorbent  fibrous  materials  are 
understood as more commonly used to reduce sound levels in two and three- wheelers. 

50 

 
 
 
 
1.2.19. Question No 19 - Do you think that the technologies available 
at this moment allow for an improvement of sound emission 
levels of L-category vehicles? 

Options: Yes, no, I don’t know 

Additional comments 

Figure 22: Answers to question 19 

“It should be possible in many cases to use silencers with less sound emission and better use 
of valves and engine mapping. however, this will in many cases come at the expense of power 
and torque, which may lead to more noise emission because of the need to use more RPMs 
to  have the  same  performance,  especially  in  vehicles  with  a  small  engine  displacement.”  – 
FEMA 

“By reducing tampering” - European Commission, JRC 

“I am not an expert in exhaust constructions” - Swiss Federal Roads Office (FEDRO) 

“Cost vs. improvement is a major consideration.” - Polaris Inc. 

"There is 2 ways to lower sound level: absorb excessive noise or don't emit excessive noise. 

Considering the L-cat, there are no room to use additional devices to absorb in an efficient 
way. Regarding a improve noise emission powertrain, I don't know any way to achieve that 
without killing seriously performances." - UTAC CERAM 

“e-mobility is acoustically the solution for L-category vehicles. But there are low-noise bikes 
out there, designed for comfortable travel. It is a matter of (sound)design!” – Umweltbundesamt 

"Disregarding if implementation of currently available technologies is cost-beneficial, they can 
allow for a minor decrease of the sound emission level. 

Only  redesigning  brand  new  engines  and  vehicles  would  allow  for  a  remarkable  sound 
emission level reduction." – ACEM 

“We do think that the actual technologies could bring to improvement in the sound emission 
levels.” - MV Agusta Motor S.p.A. 

“We  are  already  making full  use  of  currently  available  noise  reduction  technologies  without 
holding back to complete the product quality.” - Yamaha Motor Co., Ltd. 

 
 
 
 
“It depends on the amount of the required improvement.” - Ducati Motor Holding 

“Some  motorcycles  are  quieter  than  others  so  it  would  logically  follow  that  it  is  technically 
feasible to make improvements. However, there would an impact on power and torque and all 
these reductions would be in vain if consumers still purchased illegal exhausts.” - Federation 
Internationale de Motocyclisme 

"Disregarding if implementation of currently available technologies is cost-beneficial, they can 
allow for a minor improvement of the sound emission level. Going beyond a minor improvement 
of sound emission levels would require research in new technologies." - KTM AG 

“At this moment, no technologies available to bring the sound level further, at least no suitable 
ones in terms of cost efficiency or mass production feasibility.” - Honda 

“Mapping, more volume of silencers, shielded engines/gearboxes and water-cooled engines 
are given technics which lower the Sound Emission in a strong way. because the Driver often 
wants to have a high Sound emission the manufacturer of vehicles and Replacement silencers 
often uses flapsystem silencers to use Grey zones and Loop holes.”  - Ministry of Transport 
and digital Infrastructure of Germany (BMVI) 

“You can get motorcycles very silent with the current technologies, provided that this will be a 
requirement by law. If the latter is not the case then, then the vehicle may probably not be as 
exciting for the end user.” - RDW 

“Many modern motorcycles are quieter than the minimum noise limits.” Individual 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles.” - Ministry of transport and Construction of the Slovak republic 

“Technologies are available, but they have an impact in vehicle cost” - IDIADA 

“the aging process should be better” - Anonymous 

"Disregarding if implementation of currently available technologies is cost-beneficial, they can 
allow for a minor decrease of the sound emission level. 

Only redesigning brand new engines and vehicles, the noise reduction can be remarkable." – 
IMMA 

“Reductions based on current technologies are (very) limited.” - Kawasaki Motors Europe N.V. 

“To improve with the last limits of the R41.04ECE is difficult the only performance is to have a 
bigger exhaust or less power.” - LCOE 

Conclusions 

Among the  received  answers  the  percentage  of stakeholders thinking that current  available 
technologies allow for an improvement of sound emission levels of L- category vehicles double 
the number of answers indicating the opposite (61 % against 31 %) 

52 

 
 
 
1.2.20. Question  No  20  -  In  your  opinion,  which  existing  or  new 
technologies  would  allow  for  a  decrease  of  the  sound 
emission level  of  motorcycles, tricycles and quadricycles? 

For this question we received the following comments: 

“To  a  certain  extent,  quieter  exhaust  systems,  other  engine  mapping,  but  this  will  in  many 
cases come at the expense of performance and might work counterproductive if the vehicle 
needs to do a higher RPM to get the same performance.” – FEMA 

“I don't know.” - UTAC CERAM 

“Electric vehicles.” - Norwegian Public Roads Administration 

"electric 
Umweltbundesamt 

drives  proper  sound  engineering 

for 

conventional  drives" - 

"As for q. 19, combination of currently available technologies can allow for a minor decrease 
of the sound emission level. Only redesigning brand new engines and vehicles would allow for 
a remarkable sound emission level reduction. Beside vehicle specific measures, measures to 
improve rider behaviour, roadside enforcement/market surveillance will allow for a decrease 
of the real world sound emission levels." – ACEM 

“No new technology available at the moment, only the use of all the existing ones combined.” 
- MV Agusta Motor S.p.A. 

"As  in  answer  to Question  19,  any  novel  noise  reduction technologies  are  not  available  for 
now. 

What  we  can  expect  as  the  effective  one  is  sound  detection  traffic  camera  as  already 
introduced in UK and other regions. Since abnormally high sound level can hardly be emitted 
from OEM vehicles during appropriate, normal usage, such traffic cameras can be promising 
in reducing noise pollution if they are capable of detecting illegal tampering and inappropriate 
driving behaviours." - Yamaha Motor Co., Ltd. 

"Following  existing  technologies  can  for  example  lead  to  a  minor  decrease  of  the  sound 
emission level: 

- 

- 

Insulated transmission covers in order to attenuate mechanical noise 

Selecting high quality gearing so mechanical noise & vibrations can be lowered" - 

Ducati Motor Holding 

“Using properly homologated exhausts would be the single biggest factor in noise reduction.” 
- Federation Internationale de Motocyclisme 

"As with question 19, the existing technologies would eventually allow for a minor decrease of 
the  sound  emission  level.  For  a  more  ambitious  reduction  new  technologies  and  specific 
expertise would need to be developed." - KTM AG 

“No new technologies available, just the combined use of many existing ones.” – 

Honda 

“EV  and  Mild-HEV  could  bear  a  lot  of  the  engine  load  during  acceleration.  By  lowering  the 
Annex 3 Limits and the ASEP Limit curves for partial load these technics can help to lower the 
real sound emissions.” - Ministry of Transport and digital Infrastructure of Germany (BMVI) 

“Set up of bike engine performance in combination with exhaust silencer design.” - 

 
 
 
TÜV SÜD Czech s.r.o. 

“Proper silencing of the intake and exhaust system together with a proper engine mapping.” - 
RDW 

“Smart  materials  (fibrous  materials),  new  tyres,  active  noise  reduction  technologies, 
hybridation, encapsulation for quadricyles…” - Ministry of ecological transition 

"The problem is not in the manufacturing technology, but the control in use is a problem. 

Modern  technology  can  produce  much  quieter  motorcycles  than  the  default  limitations,  but 
motorcyclists often do not want very quiet motorcycles." - Individual 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles.” - Ministry of transport and Construction of the Slovak republic 

"Exhaust system refinement, intake, engine control, valve timing, cam drive" - IDIADA 

“more durable materials” - Anonymous 

"As for q. 19, combination of currently available technologies can allow for a minor decrease 
of the sound emission level. 

Only redesigning brand new engines and vehicles, the noise reduction can be remarkable. 

Beside  vehicle  specific  measures,  measures 
improve  rider  behaviour,  roadside 
enforcement/market  surveillance  will  allow  for  a  decrease  of  the  real  world  sound  emission 
level." - IMMA 

to 

“Simulation of noise levels. CFD. Structural response.” - Triumph Motorcycles 

“Reductions cannot be made based on one technology or one component. A minor decrease 
already  requires a  complete  redesign  of  a  vehicle using  all  available solutions.”  -  Kawasaki 
Motors Europe N.V. 

Conclusions 

The  scope of received  answers  is  wide.  In  some  cases  there is  a reference  to EVs,  in-use 
controls, rider’s behaviour or sound detection traffic cameras as tools allowing for a decrease 
of the sound emission level of motorcycles, tricycles and quadricycles, but these answers are 
misplaced because the question refers to existing or new technologies. 

When talking specifically about technologies allowing for a decrease of the sound emission 
level of the concerned L-category vehicles, the summarised conclusions are that from one side 
most stakeholders are not aware of new technologies that could improve sound emissions on 
L-category vehicles, and on the other side that only a combination of minor improvements on 
the existing components and systems, and in particular exhaust and intake systems, may lead 
to an improvement of the current sound levels. For a more substantial reduction of these levels 
some stakeholders reckon that a complete redesign of the powertrains would be necessary, 
and some of them name also the partial electrification as a possibility. 

54 

 
 
 
 
1.2.21. Question No 21 - In your opinion, for which of the following 
L-category vehicles  is  compliance  with  the  existing  sound 
emission limits more difficult? 

Options: L3e-A1 (light motorcycles), L3e-A2 (medium motorcycles), L3e-A3 (high performance 
motorcycles), L5e (tricycles), L3e-AxE (enduro motorcycles), L3e-AxT (trial motorcycles), L6e 
(light quadricycles), L7e (heavy quadricycles) 

Additional comments 

Figure 23: Answers to question 21 

“We do not have the e knowledge to answer this question. In general, in our opinion it is not 
the kind of L-category vehicle but the use of it that makes most of the difference.” – FEMA 

“high performance - high sound emission OR single cylinder engines - high sound emission 
due  to  lack  of  smooth  sound  (like multiple cylinder  engines)”  -  Swiss  Federal  Roads  Office 
(FEDRO) 

"As already described, in case of excessive noise vehicle need some room (length, mass, etc.) 
or fairings. An enduro motorcycle is nothing more than an engine between 2 wheels and under 
a saddle. Hard to absorb noise emission, isn't it?" - UTAC CERAM 

“We have no data about other categories.” - MV Agusta Motor S.p.A. 

"We have no idea about L6e, L7e, L3e-AxE, or L3e-AxT vehicles. For other L-cat vehicles, it 
is hard to make a comprehensive comparison because conditions vary by vehicle type even 
within the same subcategory." - Yamaha Motor Co., Ltd. 

“I  have  no  idea  about  L3e-A1,  L3e-AxE,  L3e-AxT,  L5e,  L6e,  L7e,  vehicles.”  -  Ducati  Motor 
Holding 

“The  FIM  does  not  have  practical  expertise  on  testing  road  vehicles  for  homologation.”  - 
Federation Internationale de Motocyclisme 

"Due  to  vehicle  cost,  todays  effort  to  be  compliant  with  existing  sound  emission  limits  is 
relatively high and therefore difficult to achieve. With regards to noise level limits of UNECE 

 
 
 
 
R41, vehicles of category L3e-A1 are often falling under the categories PMR<50 and therefor 
already the lower limit values apply. 

For L3e-AxE/T it is difficult to implement noise reduction functions/volumes into the vehicle, 
because of the constraints related to ergonomy given by the purpose of using these vehicles 
also/mainly in motorsport competitions. 

For  L3e-A2/A3  the  challenge  lies  within  the  expectations  and  demands  of  the  riders  with 
regards to performance (not only max. power but also the way the power is delivered). 

We have no experience with L5/6/7 therefor we could not rank those categories." - 

KTM AG 

"L3-A1  already  has  a  low  L_urban limit.  CVT's are  commonly  used for  this  segment,  which 
have added mechanical noise challenges. AxE have off road tyres resulting in higher noise 
levels. AxT have very short gearing. (but these are not used in Urban & Extra urban areas, so 
not really the cause of citizen complaints) 

In general, 2-wheelers have challenges to reduce the noise due to limited space for exhaust 
and exposed mechanicals (chain, transmission, engine, clutch, …) 

please disregard the L5, L6 & L7: we don't have any L5e, L6e, L7e Type approved models in 
EU." - Honda 

“Depends on engine/gearbox covering, performance and max. rpm” - Ministry of Transport and 
digital Infrastructure of Germany (BMVI) 

“Provided that the vehicles are high end products since this will affect the ranking. Also, the 
vehicle size will have influence on the ranking since small sizes have no room for packaging 
the sound limitation systems.” – RDW 

“Many other levers exist to lower noise emissions apart from lowering noise emission limits: 
driving  (aggressive  or  not),  traffic  in  exhaust  pipes,  road  surfaces,  etc.  The  impact  on  the 
reduction in noise emissions from the lower limits are sometimes small.” 

- 

Ministry of ecological transition 

"No IMMA reply, each individual OEM to reply" - IMMA 

Conclusions 

Some main trends may be identified regarding the difficulty to comply with the current sound 
limits for the different vehicles, but stakeholders’ points of view are not always aligned. Some 
additional remarks refer to the lack of know-how on less common vehicle categories like L5e, 
L6e and L7e, too. 

One detected feature to highlight is that the perceived difficulty to comply with the limits is quite 
different between the three L3e two-wheeler categories: L3e-A3 are understood as the ones 
having the highest difficulties, followed by L3e-A1, but for L3e-A2 results show surprisingly a 
perception of a lower difficulty. 

Finally, L5e tricycles are signaled by the stakeholders as the vehicles for whom the difficulty 
to comply with the current sound limits would be lower. 

56 

 
 
 
1.2.22. Question No 22 - According to your point of view, for which 
of the following vehicle categories a reduction on the approval 
sound emission limits would have a greater positive impact on 
road traffic noise pollution? 

(light  motorcycles),  L3e-A2 

Options: Giving a mark from 0 (minor positive impact) to 10 (greater positive impact) to: L3e-
(high  performance 
A1 
motorcycles), L5e (tricycles), L3e-AxE (enduro motorcycles), L3e-AxT (trial motorcycles), L6e 
(light quadricycles), L7e (heavy quadricycles) 

(medium  motorcycles),  L3e-A3 

Additional comments 

Figure 24: Answers to question 22 

“We do not have the knowledge to answer this question. In general, in our opinion it is not the 
kind of L-category vehicle but the use of it that makes most of the difference.” – FEMA 

“It is all about the population of these different categories in European roads.” - 

European Commission, JRC 

"As already described, a brand new vehicle is not the actual problem. Even a big reduction 
cannot have any impact on modified/tampered vehicle." - UTAC CERAM 

"The impact of reducing L-cat. sound level limits on overall traffic noise will be limited due to 
the relatively low share of L-cat. vehicles. 

Citizen complaints come from single noise events due to tampering, illegal exhausts and/or 
irresponsible riding behavior." – ACEM 

“Further reduction on type approval limits would do not have benefits on noise pollution given 
that the number of the motorcycles in the overall road traffic is small.” 

-  MV Agusta Motor S.p.A. 

"We have no idea about L6e, L7e, L3e-AxE, or L3e-AxT. For other L-cat vehicles, we are afraid 
further  reduction  of  type  approval  limits  would  have  very  few  benefits  on  noise  pollution 
considering that population of motorcycles in the overall road traffic is small. 

 
 
 
 
Apart from regulatory limits, it is also necessary to establish a system and structure such that 
education, awareness promotion, and enforcement of control for improving driving behaviors 
are provided in a continued manner." - Yamaha Motor Co., Ltd. 

"No greater impact of reducing L-cat sound level limits on overall traffic due to low share of L-
cat. 

I also believe that citizen complaints come from single noise events due to tampering, illegal 
exhausts and/or irresponsible riding behavior. 

I have no idea about L3e-AxE, L3e-AxT, L5e, L6e, L7e, vehicles." - Ducati Motor Holding 

“The  FIM  does  not  have  practical  expertise  on  testing  road  vehicles  for  homologation.”  - 
Federation Internationale de Motocyclisme 

“The impact of reducing L-cat sound level limits on overall traffic will be limited due to low share 
of  L-cat.  Also,  we  believe  that  citizen  complaints  come  from  single  noise  events  due  to 
tampering, illegal exhausts and/or irresponsible/inappropriate riding behavior.” - KTM AG 

"The impact of reducing L-cat sound level limits on overall traffic will be limited due to low share 
of  L-cat.  Also,  we  believe  that  citizen  complaints  come  from  single  noise  events  due  to 
tampering, illegal exhausts and/or irresponsible riding behavior. 

AxT & AxE share is very low compared to other L-categories and are not used in Urban or 
extra urban environment." - Honda 

“If you look at the registration numbers in the Netherlands over the past years then the effect 
on sound level emissions will have the most effect with the L3e category vehicles. However, 
further study is needed to look at the sound emissions during the leisure use of the vehicles 
since those sound emissions are expected to produce the annoying sound level emissions.” - 
RDW 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles.” - Ministry of transport and Construction of the Slovak republic 

“The impact of reducing L-cat sound level limits on overall traffic will be limited due to low share 
of  L-cat.  Also,  we  believe  that  citizen  complaints  come  from  single  noise  events  due  to 
tampering, illegal exhausts and/or irresponsible riding behavior.” - IMMA 

“As  long  as  current regulations are  not  enforced by  member  states,  any type  approval  limit 
reduction will have no significant impact. Reducing type approval limit could actually cause the 
opposite effect of more tampering.” - Kawasaki Motors Europe N.V. 

This category of vehicles are very few so the impact to improve the sound could affect no so 
much to the global noise of the traffic.” - LCOE 

Conclusions 

From the received answers, we can conclude that a reduction on the approval sound limits 
would have a greater positive impact on road traffic noise pollution mostly when applied to two-
wheelers, but without a significant difference compared to the other L-categories.  

58 

 
 
 
1.2.23. Question  No  23  -  Could  you  indicate,  according  to  your 
understanding,  which  sound  level  limit  reduction  (if  any) 
should apply to each of the following categories? 

Options: For L3e with PMR ≤ 25, L3e with PMR > 25 and PMR ≤ 50, L3e with PMR > 50, L5e, 
L6e, L7e: Unchanged, -1 dB(A), -2 dB(A)), More than -2 dB(A), other 

Answers received as other 

Figure 25: Answers to question 23. 

-5  db;  corresponding  limit  as  L3e  based  on  the  PMR;  the  80  db(A)  for  often  low  powered 
vehicles  which  shielded  engines  is  possible  without  dramatic  changes.  Anti-  tampering 
requirements have also been modified for L7e; 76 dB(A); to bring them closer to L3e-A3 SL 

Additional comments 

“The impact of lower sound limits for L-cat vehicles will be negligible. Noise annoyance is not 
caused by L-cat vehicles that are in original condition and used in an appropriate way, The 
problem with noise annoyance is caused by all kinds of vehicles (not only L-cat vehicles) that 
are tampered with, are fitted with illegal mufflers, driven with too high RPM, are driven with 
loud electronic devices (radios, but also devices that enhance the vehicle sound emission) etc. 
Lowering the sound emission limits will not solve the problem of noise annoyance.” – FEMA 

“Creo que es necesario cambiar el método de ensayo.” - Ayuntamiento de Madrid 

“It should be the target to get closer to the level of noise reconvened for exposed personnel in 
Europe” - European Commission, JRC 

“as already discussed in GRBP (UNECE) in Geneva, "nice" values on paper don't solve the 
problem! The problem is, in fact, tampering as well as exhausts with clappets!” - Swiss Federal 
Roads Office (FEDRO) 

"As already described, a brand new vehicle is not the actual problem. 

Even a big reduction cannot have any impact on modified/tampered vehicle. However, 80 dB 
may be a little bit high for quadricycle with room and fairings." - UTAC CERAM 

“We believe that the limit values for L3e category vehicles is sufficient, and that tampering is 
the main problem.” - Norwegian Public Roads Administration 

 
 
 
 
“The sound limits are not the problem, but rather the loop holes in the regulatory system and 
the difficulty of road-side checks of conformity.” – Umweltbundesamt 

"The  impact  of  any reduction  of  L-cat.  sound  level  limits  on  overall traffic  noise will  be  very 
limited/negligible  due  to  the  relatively  low  share of  L-cat.  vehicles. We  do  not  consider  any 
reduction  of  the  vehicle  type  approval  sound  level  limits  as  appropriate.  Countermeasures 
against illegal aftermarket mufflers and illegal tampering of vehicles should have priority over 
setting up lower sound emission limits for type approval, to close the gap between real world 
and type approval. The sound level emitted by L category vehicles is the sum of: 

1. 

2. 

3. 

vehicle sound, 

noise caused by inappropriate rider behaviour, 

noise caused by aftermarket silencing systems. 

The vehicle manufacturer is responsible only for point 1." - ACEM 

“For  the  L3  vehicles  with  no  new  technology  available  the  reduction  of  sound  level  limit 
reduction is not appropriate.” - MV Agusta Motor S.p.A. 

"We do not consider any reduction of the sound limits for vehicle type approval as appropriate. 
Countermeasures against illegal aftermarket mufflers and illegal tampering of vehicles should 
have priority over setting up lower sound emission limits for type approval, to close the gap 
between real world and type approval. The sound level emitted by L category vehicles is the 
sum of: 

1. 

2. 

3. 

vehicle sound, 

noise caused by inappropriate rider behavior 

noise caused by aftermarket silencing systems. 

Through UNR41-05, contribution of OEM vehicles to noise pollution would be minimal if they 
are operated in an appropriate manner like majority of riders do." - Yamaha Motor Co., Ltd. 

"The sound level emitted by L category vehicles is the sum of: 

1. 

2. 

3. 

vehicle sound, 

noise caused by inappropriate rider behaviour 

noise caused by aftermarket silencing systems. 

The vehicle manufacturer is responsible only for point 1. 

I do not consider any reduction of vehicle type approval as appropriate 

Also, I believe that citizen complaints come from single noise events due to tampering, illegal 
exhausts and/or irresponsible riding behavior. 

I have no idea about L5e, L6e, L7e, vehicles." - Ducati Motor Holding 

“The  FIM  does  not  have  practical  expertise  on  testing  road  vehicles  for  homologation.”  - 
Federation Internationale de Motocyclisme 

"We  do  not  consider  any  reduction  of  the  sound  level  limit  for  vehicle  type  approval  as 
appropriate.  Countermeasures  against  illegal  aftermarket  mufflers  and  illegal  tampering  of 
vehicles should have priority over setting up lower sound emission limits for type approval, to 
close the gap between real world and type approval. The sound level emitted by L category 
vehicles is the sum of: 

1. 

2. 

3. 

vehicle sound, 

noise caused by inappropriate rider behaviour 

noise caused by aftermarket silencing systems. 

60 

 
The vehicle manufacturer is responsible for point 1." - KTM AG 

“Same as above question 23: due to limited share of L-cat in overall traffic, the impact should 
not be overestimated. We believe citizen complaints are due to single events (tampering, illegal 
exhaust,  irresponsible  riding  behavior,  older  motorcycles…),  for  which  other  measures  will 
have more impact (enforcement, PTI…).” – Honda 

“SPL-reduction on high performance motorbikes (more than 70 kW) which high rpm is much 
more expensive than the reduction of L3e-A1 or L7e. The SPL of L5e, L6e and L7e are very 
high and the same like 1997. These vehicles use the same engine during the last 25 years. 
Anti-tampering of L7e is also very important for real Sound emissions.” - Ministry of Transport 
and digital Infrastructure of Germany (BMVI) 

“-2 dB should be achievable. Not only the Lurban should be reduced, it should apply to all driving 
conditions. Besides the reduction in sound level limits a limitation of possible changes during 
in service should also the taken into account. Changes to original equipment should not be 
possible unless they have an equal or better performance as the original equipment.” - RDW 

“This question would require a study on a broad sample of vehicles. We don’t have enough 
elements to propose sound level limit reduction.” - Ministry of ecological transition 

“Exhaust modifications are a problem” - Individual 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles.” - Ministry of transport and Construction of the Slovak republic 

"L3e vehicles are more evolved and refined. Noise reduction is more a problem of cost. 

For L5, L6 and L7, the level of refinement is low and there is more room for noise improvement. 
Also 80 dB(A) is not acceptable; too high" – IDIADA 

"We do not consider any reduction of the sound emission limits+C3 for vehicle type approval 
as appropriate. Countermeasures against illegal aftermarket mufflers and illegal tampering of 
vehicles should have priority over setting up lower sound emission limits for type approval, to 
close the gap between real world and type approval. The sound level emitted by L category 
vehicles is the sum of: 

1. 

2. 

vehicle sound, 

noise caused by inappropriate rider behaviour 

noise  caused  by  aftermarket  silencing  systems.  The  vehicle  manufacturer  is 

3. 
responsible only for point 1. 

Due to limited share of L-cat in overall traffic, any reduction would have a negligible impact." - 
IMMA 

“As  long  as  current regulations are  not  enforced by  member  states,  any type  approval  limit 
reduction will have no significant impact. Reducing type approval limit could actually cause the 
opposite effect of more tampering.” - Kawasaki Motors Europe N.V. 

Conclusions 

When asked about eventual sound level limit reductions for L-category vehicles, stakeholders’ 
majority of opinions lean for keeping the limits unchanged for all categories, and specially for 
two-wheelers, where the percentage of answers in this direction is the highest. 

For L3e motorcycles with PMR > 50 there is a relevant number of opinions where a reduction 
of 2 dB(A) is understood as convenient. 

We find the highest number of opinions indicating the convenience of lower sound limit among 
tricycles  and  quadricycles,  where  limit  reductions  over  2  dB(A)  come  as  the  second  most 
considered option behind the “no reduction” one. 

 
 
1.2.24. Question No 24 - According to your point of view, how big do 
you  think  the  financial  impact  of  lowering  Euro  5  sound 
emission  limits  would  be  on  motorcycles,  tricycles  and 
quadricycles manufacturers? 

Please   indicate which percental increase of the global development and manufacturing costs 
do you estimate for each case: 

Options: For motorcycles, tricycles and quadricycles: 

Development costs - Null, ˂ 5 %, 5 ≤ 10 %, 10 ≤ 25 %, higher 

Manufacturing costs - Null, ˂ 5 %, 5 ≤ 10 %, 10 ≤ 25 %, higher 

Figure 26: Answers to question 24 

Additional comments 

“We do not have the knowledge to answer this question.” – FEMA 

“No feelings on the cost at the moment” - European Commission, JRC 

“lowering  sound  emission  limits  for  1  dB(A)  or  2  dB(A),  respectively,  isn't  that  much.  So 
development costs may not be that high.” - Swiss Federal Roads Office (FEDRO) 

"I  gave  you  estimation,  not  more.  For  my  side,  motorcycles  are  the  most  complicated  and 
expensive case." - UTAC CERAM 

“This question is really ill posed: Can anyone really estimate the cost effect of a very unspecific 
measure (lowering the limit: by how much????). But in general, money is spent to increase the 
sound  so  making  vehicles  less  noisy  is  a  matter  of  saving  money  in  most  cases.”  - 
Umweltbundesamt 

“It is certain such costs would increase, but it depends on the degree of reduction and vehicle 
types and categories and thus our choice is "no answer".” - MV Agusta Motor S.p.A. 

“It is certain such costs would increase, but it depends on the degree of reduction and vehicle 
types and categories and thus our choice is "no answer".” - Yamaha Motor Co., Ltd. 

“This  strictly  depends  on  the  level  of  reduction  and  vehicle  characteristics”  -  Ducati  Motor 
Holding 

“Assuming a meaningful improvement presupposes a drivetrain and exhaust redesign which 
would  be  a  significant  cost  to  all  manufacturers.  In  most  cases,  this  may  not  increase 

62 

 
 
manufacturing costs beyond tooling, material and retraining. However, it should be noted that 
redesigns are expensive and have to be amortised over relatively few vehicles which adds cost 
to the consumer.” - Federation Internationale de Motocyclisme 

"It is not possible to answer this question by means of the above table. 

Within 
architectures) are too big to give a general answer. 

the  Motorcycle  categories 

the  variabilities  (sub-categories,  different  vehicle 

For  minor  reductions  of  the  sound  level  limit  the  increase  in  development  cost  may  be 
estimated between 5 % and 10 %. Even a general prediction of the manufacturing cost is not 
possible, given the variety of potential technical solutions and their individual application on 
different vehicles. 

Going beyond a minor reduction would require much higher development effort. The related 
challenges  would  need  to  be  addressed  by  means  of  research  projects  first,  to  gather  the 
general know-how. It may be expected that further investments in R&D infrastructure (acoustic 
chambers, equipment, software) would be necessary. And last but not least, human resources 
with specific know-how must be hired or trained." 

- 

KTM AG 

“This depends very much on the level of reduction and vehicle characteristics. Most vehicles 
will have a substantial cost impact, even with moderate reductions.” - Honda 

“For  Quadri-  and  tricycles  the  technic  is  given  (shields  engines/gearboxes;  water-  cooling, 
bigger silencers). For high performance motorbikes the development and manufacturing costs 
will be higher.” - Ministry of Transport and digital Infrastructure of Germany (BMVI) 

“This  is  up  to  the  vehicle  manufacturers  to  answer.  For  low  end  vehicle  manufactures  the 
percentages can be much higher than for the high end manufacturers since they can have a 
bigger model range and revenue.” - RDW 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles.” - Ministry of transport and Construction of the Slovak republic 

"No IMMA reply, each individual OEM to reply" - IMMA 

“Difficult to answer as it depends on the amount of the reduction (if possible at all).” - 

Kawasaki Motors Europe N.V. 

Conclusions 

The financial impact of lowering Euro 5 sound emission limits on motorcycles, tricycles and 
quadricycles is estimated mostly between the “˂ 5 %” and the “5 ≤ 10 %” increase of total costs 
ranges. The incidence on development and manufacturing costs vary significantly depending 
on  the  considered  financial  impact  level:  when  this  impact  is  deemed  to  be  up  to  10  %, 
manufacturing costs are generally understood as slightly higher than development costs, but 
when  the  considered  financial  impact  is  between  10  %  and  25  %  the  highest  number  of 
answers refers to the development costs and production costs percentage is lower. 

 
 
 
 
1.2.25. Question No 25 - What would be, from your understanding, 
the  cost/benefit  ratio  threshold  in  case  that  lower  sound 
emission level regulatory limits applied? 

Cost/benefit ratio must be understood as the balance between the financial cost for improving 
the vehicle’s sound level performance and the environmental benefits. 

Options: For motorcycles, tricycles and quadricycles: 

A sound limit reduction of 1 dB(A) results in more benefits than costs  

A sound limit reduction of 1 dB(A) results in less benefits than costs  

A sound limit reduction of 2 dB(A) results in more benefits than costs  

A sound limit reduction of 2 dB(A) results in less benefits than costs  

A sound limit reduction ≥ 3 dB(A) results in more benefits than costs  

A sound limit reduction ≥ 3 dB(A) results in less benefits than costs 

Additional comments 

Figure 3: Answers to question 25 

“We do not have the expertise knowledge to answer this question in detail, but in general we 
see no benefits in lower sound limits. See answer to Q23..” - FEMA 

“I  cannot  understand  the  question...perhaps  the  translation  is  confusing  things.  No  answer 
because of this.” - Polaris Inc. 

"As a TS, I cannot find any benefits for a reduction for my point of view. As a city resident or a 
pedestrian or even a road user, I may find a benefit but how about the cost? 

Tricky question." - UTAC CERAM 

64 

 
 
 
“I don't think anyone can answer this question reliably without a proper study.” – 

Umweltbundesamt 

“The fleet of L-category vehicles is limited compared to other road vehicles, hence a reduction 
of limits for L-category vehicles will have a limited/negligible environmental benefit.” - ACEM 

“The fleet of L-category vehicles is limited compared to other road vehicles, hence a reduction 
of limits for L-category vehicles may have limited/marginal environmental benefit.” - MV Agusta 
Motor S.p.A. 

"Since the environmental benefits are not quantified, we are unable to compare the costs. We 
would like to be given the quantified benefits and their rationale, as well as justification thereof 
established by the third party. 

Besides,  without  knowing  how  much  reduction  is  applied,  it  is  not  possible  to  estimate  the 
costs. It is difficult to estimate the costs because sound sources and their conditions differ by 
vehicle type, and besides, general cost estimation itself requires man-power." - Yamaha Motor 
Co., Ltd. 

“The fleet of L-category vehicles is limited compared to other road vehicles, hence a reduction 
of limits for L-category vehicles may have limited environmental benefit.” - 

Ducati Motor Holding 

“The  FIM  does  not  have  practical  expertise  on  testing  road  vehicles  for  homologation.”  - 
Federation Internationale de Motocyclisme 

“The fleet of L-category vehicles is limited compared to other road traffic, hence a reduction of 
limits for L-category vehicles may have limited/marginal environmental benefit.” - KTM AG 

“Limited  fleet  of  L-category  vehicles  is  limited  compared  to  other  road  vehicles,  hence  a 
reduction  of  limits  for  L-category  vehicles  may  have  only  limited  environmental  benefit.”  - 
Honda 

"The main question is: What Kind of motorcycles will be the Outcome of such a modification. 

As an example: Today a high-performance motorbike have 1.000 cc, 200 kg, 200 PS and a 
flap system silencer. If you want to reduce the SPL about 2 dB(A) the costs are higher than 
the  benefit,  if  you  do  not  install  RD-ASEP  with  randomized  tests  and  low  partial-load  and 
cruising ASEP-Limit-curves. For a low power motorcycles with 500 cc, 170 kg, 48 PS and a 
Standard silencer the reduction of 2 dB(A)it is in the other way around (A sound limit reduction 
of 2 dB(A) results in more benefits than costs). 

For Tricylcles and Quadricycles it is easier to give a General answer." - Ministry of Transport 
and digital Infrastructure of Germany (BMVI) 

“The effect of a noise limit under all operating conditions and the prevention of post- registration 
adjustments that create a higher noise level than the original can have more effect than just 
lowering the noise limit.” – RDW 

“We have no data to define a costs/benefits threshold.” - Ministry of ecological transition 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles.” - Ministry of transport and Construction of the Slovak republic 

“The fleet of L-category vehicles is limited compared to other road vehicles, hence a reduction 
of limits for L-category vehicles may have limited/marginal environmental benefit.” - IMMA 

“Benefits of lowering the sound emission level will have limited effect as the fleet of L category 
vehicles  is  small  compared  to  other  vehicles.  Also,  any  benefit  will  not  reduce  real  sound 
emissions  as  long  as  the  regulations  are  not  enforced  in  each  member  state.”  -  Kawasaki 
Motors Europe N.V. 

 
 
Conclusions 

Stakeholders’ understanding regarding cost/benefit ratio threshold in case of lower regulatory 
limits on sound emission level where applied are not uniform. 

A summarized conclusion would be that for reductions resulting in more benefits than costs, 
for L3e a reduction of 1 dB(A) is more plausible and for three- and four- wheelers a reduction 
of 2 dB(A) is more beneficial. 

When looking at answers indicating less benefits than costs, we find that a 1 dB(A) reduction 
is  a  more  common  choice  than  a  2  dB(A)  reduction  and  that  a  3  dB(A)  reduction  is  not 
considered for this topic. 

66 

 
 
 
1.2.26. Question  No  26  -  According  to  your  understanding,  what 
would  be  the  maximum  increase  in  vehicle’s  selling  price 
tolerated  by  the  market  for  motorcycles,  tricycles  and 
quadricycles with a lower sound emission level? 

Please indicate which percentual increase of the vehicle’s final price you consider as critical 
threshold for each case: 

Options: For motorcycles, tricycles and quadricycles: 0 %, ˂ 2 %, 2 ≤ 5 %, 5 ≤ 10 %, higher 

Additional comments 

Figure 28: Answers to question 26 

“Currently, sound emission is not part of the specifications that are given to the customer in 
advertisements, brochures, manufacturers' websites etc. It is also not a major criterium for the 
buyer. For some kinds of motorcycles, a nice sound is important and  part of the motorcycle 
experience (e.g. Harley-Davidson), for other kinds it is no issue. Price increases because of 
noise  emission  reduction  measures  will  just  be  seen  as  price  increases  and  not  be 
understood.” – FEMA 

“Motorcycles  should  be  affordable  so  buyers  should  not  be  charged  too  much  for  the 
development  of  more  silent  motorcycles.  Furthermore,  the  environmental  aspect  should  be 
taken into account - motorcycles are consuming less (CO2) and need less space, especially 
in urban areas” - Swiss Federal Roads Office (FEDRO) 

"In my opinion, no one cares about its own sound level. So no price raising is acceptable. 

Quadricycles is a tough market with close prices. Hard to convince any customer: guess what? 
For a 10 % expensive you get a 1 dB lower vehicle". 

Regarding motorcycles, I still think that the very first buy after the bike is replacement exhaust 
muffler. How to sell an expensive sound level decrease? I don't know. 

Probably the wrong way here." - UTAC CERAM 

“Again, a strange question: What amounts to non-tolerance: No longer riding a bike?” 

 
 
 
 
– Umweltbundesamt 

“Motorcyclists would not find added value in quieter vehicles taking into account that with the 
current levels of noise emissions in normal use we believe they do not cause annoyance, so 
we will not be able to pass on the costs incurred on retail prices.” - MV Agusta Motor S.p.A. 

“Both consumers and society would hardly find worthiness in further quieter vehicles whose 
current sound emission levels are acceptably low in real-world traffic, and therefore we will be 
unable to pass the incurred costs on retail prices.” - Yamaha Motor Co., Ltd. 

“It is not possible to estimate because the cost increase will depend on the final sound level 
limits and also on the vehicle type/characteristics they will apply to.” - Ducati Motor Holding 

“Reduced noise is not a consumer priority and therefore consumers would not pay more for a 
quieter vehicle. In fact, with a handful paying extra for a louder vehicle, it would suggest that 
in fact  the  opposite  is  the  case.  The  notable  exception  may  be  in  fleet  sales.”  -  Federation 
Internationale de Motocyclisme 

"We  don't  have  such  information  available.  But  it  is  clear  that  in  the  end  the  necessary 
expenses for the reduction of noise emissions will have to payed by the customers. Knowing 
that most our customers are using vehicles in type approved condition, and using their vehicles 
in  a  responsible  manner,  it  may  be  expected  that  many  of  those  customers  might  not 
understand  why  they  have  to  pay  more. Whether  or  not  they  are  anyway  accepting  to  pay 
more, we don't know yet." - KTM AG 

"Difficult to estimate as the cost increase will depend on the final sound level limits and also 
on the vehicle type/characteristics they will apply to. Drastic reductions may eliminate certain 
motorcycle  types  due  to  un-feasibility.  It  also  depends,  if  the  customer  will  feel  lower  noise 
emissions as added value. Some customers today are willing to pay more for MORE noise." - 
Honda 

“The reason is that a governmental agency should focus on safety, environmental and health 
aspects rather than the pricing of vehicles in the market.” - RDW 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles.” Ministry of transport and Construction of the Slovak republic 

“No IMMA explanation, (Each individual OEM to reply)” - IMMA 

“Any  increase  in  selling  price  will  have  a  negative  effect.  We  already  have  customers 
complaining about the lack of sound of our current products. We don't expect customers are 
willing to pay more for lower sound emissions.” - Kawasaki Motors Europe N.V. 

Conclusions 

When  questioned  on  price  increase  tolerated  by  the  market  for  motorcycles,  tricycles  and 
quadricycles emitting  a  lower  sound  level,  stakeholders’  answers  change  depending  on the 
vehicle category. 

For tricycles and quadricycles conclusions are that the number of stakeholders understanding 
that  no  increase  on  price  would  be  tolerated  is  similar  to  the  number  of  stakeholders 
understanding that a threshold up to 5 % on price increasing would be tolerated. 

For  motorcycles,  conclusions  are  less  clear.  We  see  that  the  number  of  stakeholders 
understanding that no increase on price would be tolerated is the highest, but the number of 
stakeholders  understanding that  a threshold from  2 % to  5  %  on  price  increasing  would be 
tolerated is higher than the number of stakeholders understanding that a increase up to 2 % 
on price would be tolerated. 

68 

 
 
1.2.27. Question No 27 - According to your point of view, in the event 
of new lower sound emission level limits being defined, which 
would  be  the  timeframe  needed  by  the  manufacturers  to 
implement the modifications in their vehicles to fulfil the new 
limits? 

Please  indicate  your  estimated  timeframe  for  each  vehicle  category  depending  on  the 
requested sound improvement degree. 

Options: For motorcycles, tricycles and quadricycles: 

1 dB(A) reduction: ˂ 2 years, 2 ≤ 4 years, more than 4 years 

2 dB(A) reduction: ˂ 2 years, 2 ≤ 4 years, more than 4 years 

>3 dB(A) reduction: ˂ 2 years, 2 ≤ 4 years, more than 4 years 

Figure 29: Answers to question 27 (Motorcycle) 

 
 
 
Figure 30: Answers to question 27 (Tricycle) 

Additional comments 

Figure 31: Answers to question 27 (Quadricycles) 

“As a user organization we do not have the knowledge to answer this question.” – 

FEMA 

“massive noise disturbance, especially in the alps (pass roads in summertime)” - 

Swiss Federal Roads Office (FEDRO) 

“Technology  is  quicker  than  actual  implementation  after  design,  sourcing,  validation  and 
certification. Most notable changes will not occur in less than 4 years.” - Polaris Inc. 

"Motorcycles: 1 dB is probably reachable. Above this that doesn't make sense, unless price 
raises 2 times. 

70 

 
 
 
Tricycles: there is some extra room and most of the time fairings. Improvements are probably 
possible. But -3 is certainly hard. 

Quadricycles:  there  is  some  extra  room  and  most  of  the  time  fairings.  Improvements  are 
probably possible." - UTAC CERAM 

“A complete redesign of the vehicle and engine will be necessary. Reducing limits would mean 
that mechanical noise becomes a more relevant (if not the dominant) noise source, which is 
much more expensive to address as new technologies would need to be developed for this.” - 
ACEM 

“To reduce the sound level, a complete redesign of the vehicle and the engine is necessary, 
which requires the development of new technologies which takes a long time.” - MV Agusta 
Motor S.p.A. 

“A complete redesign of vehicles and engines will become necessary if the type approval limit 
values are further reduced.” - Yamaha Motor Co., Ltd. 

“A complete redesign of vehicles and engines will become necessary if the type approval limit 
values will be reduced.” - Ducati Motor Holding 

“Previous changes to regulation have taken more than 4 years to reach the market, particularly 
if  they  require  a  redesign  as  this  would  undoubtedly  do.”  -  Federation  Internationale  de 
Motocyclisme 

“Difficult to estimate as the development time will depend on the final sound level limits and 
also  on  the  vehicle  type/characteristics  they  will  apply  to.  Minimum  4  Years  would  be  a 
reasonable transitional period for -1db. Others will require more. No comments for tricycles & 
quadricycles as we do not have such products in EU.” – 

Honda 

“Certain motorcyclists see (loud) motorcycle sound emission as part of the experience. Already 
we see tampering and replacement of original silencers by after- market silencers (often not 
homologated for road use). Almost all new Harley- Davidsons are directly after purchase fitted 
with  after-market  silencers.  Instead  of  lowering  the  limits,  better  enforcement  would  be  the 
better choice to reduce noise annoyance.” – FEMA 

“La reducción de los límites debe ir acompañada de una fuerte campaña de concienciación y 
de control.” - Ayuntamiento de Madrid 

“It all depends on the surveillance of the noise level made after type approval (in-use control)” 
- European Commission, JRC 

“definitely yes! read motorcycle tests and you will find always about the same statement: "it 
sounds not too bad but in earlier days the sound was more powerful"” - Swiss Federal Roads 
Office (FEDRO) 

"For  the  time  being  the  replacement  aftermarket  is  consequent.  Substantial  lowering  of  the 
limit will drive to a huge growing. And the tampering will be the rule on road. Frankly speaking, 
the wrong way. A rule must be acceptable in order to be adopted." 

- 

UTAC CERAM 

“We believe that many motorcyclists love their vehicle sound, and that substantially lowered 
limits  unfortunately  may 
tampering  practices.”  -  Norwegian  Public  Roads 
Administration 

increase 

"Reducing  type  approval  limits  risks  to  drive  even  more  customers  into  tampering  and  to 
purchase illegal aftermarket systems. 

The amount of owners that like distinctive sound of their motorcycle will not change when limits 
are lowered. With drastically lowered sound level limits, we expect that more people will try to 

 
 
create the sound that they want instead. This will not change as long as there are no adequate 
means as enforcement." - ACEM 

“Bikers love the distinctive sound of their motorcycle and this won't change when the limits are 
lowered. We therefore believe that more riders will buy illegal aftermarket systems to create 
the sound they want.” - MV Agusta Motor S.p.A 

“Reducing  type  approval  limits  risks  to  drive  even  more  customers  to  purchase  illegal 
aftermarket systems.” - Yamaha Motor Co., Ltd. 

"Reducing  type  approval  limits  risks  to  drive  even  more  customers  to  purchase  illegal 
aftermarket systems. 

Some owners/riders like distinctive sounding motorcycles. The amount of owners that like such 
sound will not change when limits are lowered. With drastically lowered sound level limits, we 
expect that more people will try to create the sound that they want instead. This will not change 
as long as there are no adequate means as enforcement." - Ducati Motor Holding 

“It is difficult to estimate, but a minority do want louder motorcycles.” - Federation Internationale 
de Motocyclisme 

"Reducing  type  approval  limits  risks  to  drive  even  more  customers  to  purchase  illegal 
aftermarket systems. The amount of owners that like distinctive sound of their motorcycle will 
not change when limits for vehicle type approval are lowered. With drastically lowered sound 
level limits, we expect that more people will try to create the sound that they want instead (i.e. 
via  tampering  or  riding  behaviour).  This  will  not  change  as  long  as  there  are  no  adequate 
means of enforcement." - KTM AG 

“Some  owners/riders  like  distinctive  sounding  motorcycles.  The  amount  of  owners  that  like 
such sound will not change when limits are lowered. With drastically lowered sound level limits, 
we expect that more people will try to create the sound that they want instead. This will not 
change as long as there are no adequate means as enforcement.” - Honda 

“If you do not have better  anti-tampering requirements this will be  one  effect.” - 

Ministry of Transport and digital Infrastructure of Germany (BMVI) 

“2  to  4  years  should  be  achievable  for  existing  vehicle  types  and  <  2  years  should  be 
achievable for new vehicle types. The past has proven that this is achievable.” - RDW 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles.” Ministry of transport and Construction of the Slovak republic 

“A complete redesign of the vehicle and engine will be necessary. Reducing limits would mean 
that mechanical noise becomes a more relevant (if not the dominant) noise source, which is 
much  more  expensive  to  address.  And  for  which  new  technologies  would  need  to  be 
developed.” – IMMA 

Conclusions 

The main trends among the answers received for each vehicle category have similar profiles, 
but  there  are  nuances  between  the  answers  given  for  motorcycles  and  those  given  for  the 
other categories. 

For a 1 dB(A) reduction, an up to two-year period is understood as likely for L5e, L6e and L7e, 
but for L3e a more than four years period has the same number of answers as an up to two-
year period, showing some disparity of opinions among stakeholders. 

For a 2 dB(A) reduction we see that for motorcycles the percentage of answers signaling a 
more than 4 year period is the highest, but for tricycles and quadricycles the number of answers 
indicating an up to 2-year period are equal or higher than those stating a more than 4 year 
period. 

72 

 
For the case of reduction over 3 dB(A) the percentage of answers signaling a more than 4 year 
period is the highest for all vehicles, but the margin is much bigger for motorcycles than for 
tricycles and quadricycles. 

1.2.28. Question No 28 - In case sound level limits were substantially 
lowered,  do  you  think  this  would  lead  to  an  increase  of  the 
tampering practices of the concerned L-category vehicles by 
users? 

Options: Yes, no, I don’t know 

Additional comments 

Figure 32: Answers to question 28 

“I'm  not  sure  that  I  understand  the  question,  but  if  you  want  to  know  whether  lower  sound 
emission levels will lead to less noise annoyance, the answer is no. Noise annoyance by L-
category  vehicles  is  caused  by  tampering,  the  fitting  of  after-market  exhaust  with  a  higher 
sound emission and inappropriate driving style. The sound emission limits hardly play a role 
here.” – FEMA 

“Maybe. Tampering will always be taking part as long as "masculinity" is defined by powerful 
sound...” - Swiss Federal Roads Office (FEDRO) 

"How many vehicles still use original or genuine exhaust devices? 

If you search within any used marketplace, you will find tons of ""brand new exhaust system"". 
That indicates that customer did not even drive one time with the original exhaust system. 

How could Regulation limits for type approval influence that?" - UTAC CERAM 

“We believe that increased in-use control will lower the experienced noise from motorcycles 
by the public, as the number of tampered motorcycles will be lower.” - 

Norwegian Public Roads Administration 

“More effective enforcement/in-use controls based on current sound level limits would already 
translate into an improvement of real world sound emission levels.” – ACEM 

“Controls  in  use  should  detect  vehicles  that  have  been  illegally  tampered  with.  We  do  not 
believe  that  the  reduction  of  the  noise  emission  limits  for  type  approval  produces  direct 
benefits. If effective controls are implemented on vehicles in use, we believe there will be an 
improvement in environmental noise.” - MV Agusta Motor S.p.A. 

 
 
 
"We believe the main target of in-use controls should be illegally tampered vehicles, although 
we do not have supporting data on hand. Further reduction in the type approval sound emission 
limits would hardly yield direct benefits. It is often said enough controls are not conducted by 
enforcement  authorities.  Without  adequate  exercise  of  controls  over  in-use  vehicles, 
improvements in environmental noise by means of reduction in type approval limits would not 
be expected. We should start discussion about lowering the limits for the first time when the 
effective enforcement system has been established." - Yamaha Motor Co., Ltd. 

"The main target of in-use controls should be recognizing the use of illegally tampered vehicles. 

More  effective  enforcement/  in-use  controls  based  on  the  current  level  limits  would  already 
translate into an improvement of the real world sound emission level. 

Setting lower sound level limits only, without enforcement, will have no effect." - 

Ducati Motor Holding 

“As annoyance is largely caused by tampering, the question is whether the sound level values 
are average or peak.” - Federation Internationale de Motocyclisme 

“More effective enforcement/in-use controls based on current sound level limits would already 
translate into an improvement of real world sound emission levels, and thus are considered 
more effective than lowering the sound level limits.” - KTM AG 

“We  believe  the  other  way  around  is  appropriate:  in-use controls  will  reduce  the  amount  of 
aftermarket mufflers/ tampering/ … and thus improving real world noise. Setting lower sound 
level limits only, without enforcement, will not have effect.” - 

Honda 

“If you do not do a high number of roadside checks, the manipulations of OEM- silencers or 
the use of not approved replacement silencers or manipulated replacement silencers will have 
a higher influence in the negative way than the Sound Pressure Level reduction will have it in 
the positive way.” - Ministry of Transport and digital Infrastructure of Germany (BMVI) 

“Sound level emissions are hard to measure during roadside inspections, so it will always result 
in a several dB’s margin compared to type approved. This will give room and allowance for 
tampering. A proper test procedure with for instance a portable sound emissions measurement 
system could help with this matter and avoid mis-use by vehicle owners. Also, a wider range 
of engine speeds for the stationary sound level could be taken into account. Besides this it is 
also important that mufflers/catalytic converters can be identified (type approval number should 
be readable for 30 years) and that the exhaust system is a “closed” system, so fully welded 
instead of removable parts.” – RDW 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles.” - Ministry of transport and Construction of the Slovak republic 

“It depends on the law reinforcement applied” IDIADA 

"Reducing  type  approval  limits  risks  to  drive  even  more  customers  to  purchase  illegal 
aftermarket systems. The total number of owners that like distinctive sound of their motorcycle 
will not change when limits are lowered. With drastically lowered sound level limits, we expect 
that more people will try to create the sound that they want instead. This will not change as 
long as there are no adequate means as enforcement." - IMMA 

“Yes, especially with a lack of enforcement, a reduction in the sound level limit will lead to more 
tampering.” - Kawasaki Motors Europe N.V. 

Conclusions 

There is a high percentage of answers (67 %) were stakeholders’ opinion is that in the event 
sound level limits were substantially lowered this would lead to an increase of the tampering 
practices by the users of the concerned L-category vehicles. 

74 

 
1.2.29. Question No 29 - Do you think that lowering sound emission 
level limits could translate into an improvement of the sound 
emission level values collected through in-use controls? 

Options: No improvement, very small improvement, small improvement, medium improvement, 
high improvement, I don’t know 

Additional comments 

Figure 33: Answers to question 29 

“I'm  not  sure  that  I  understand  the  question,  but  if  you  want  to  know  whether  lower  sound 
emission levels will lead to less noise annoyance, the answer is no. Noise annoyance by L-
category  vehicles  is  caused  by  tampering,  the  fitting  of  after-market  exhaust  with  a  higher 
sound emission and inappropriate driving style. The sound emission limits hardly play a role 
here.” – FEMA 

“Maybe. Tampering will always be taking part as long as "masculinity" is defined by powerful 
sound...” - Swiss Federal Roads Office (FEDRO) 

"How many vehicles still use original or genuine exhaust devices? 

If you search within any used marketplace, you will find tons of ""brand new exhaust system"". 
That indicates that customer did not even drive one time with the original exhaust system. 

How could Regulation limits for type approval influence that?" - UTAC CERAM 

“We believe that increased in-use control will lower the experienced noise from motorcycles 
by the public, as the number of tampered motorcycles will be lower.” - 

Norwegian Public Roads Administration 

“More effective enforcement/in-use controls based on current sound level limits would already 
translate into an improvement of real-world sound emission levels.” - ACEM 

“Controls  in  use  should  detect  vehicles  that  have  been  illegally  tampered  with.  We  do  not 
believe  that  the  reduction  of  the  noise  emission  limits  for  type  approval  produces  direct 
benefits. If effective controls are implemented on vehicles in use, we believe there will be an 
improvement in environmental noise.” - MV Agusta Motor S.p.A. 

"We believe the main target of in-use controls should be illegally tampered vehicles, although 
we do not have supporting data on hand. Further reduction in the type approval sound emission 
limits would hardly yield direct benefits. 

It  is  often  said  enough  controls  are  not  conducted  by  enforcement  authorities.  Without 
adequate exercise of controls over in-use vehicles, improvements in environmental noise by 
means of reduction in type approval limits would not be expected. We should start discussion 

 
 
 
about  lowering  the  limits for  the first time  when  the  effective enforcement  system  has  been 
established." – Yamaha Motor Co., Ltd. 

"The main target of in-use controls should be recognizing the use of illegally tampered vehicles. 

More  effective  enforcement/  in-use  controls  based  on  the  current  level  limits  would  already 
translate into an improvement of the real-world sound emission level. 

Setting lower sound level limits only, without enforcement, will have no effect." - 

Ducati Motor Holding 

“As annoyance is largely caused by tampering, the question is whether the sound level values 
are average or peak.” - Federation Internationale de Motocyclisme 

“More effective enforcement/in-use controls based on current sound level limits would already 
translate into an improvement of real-world sound emission levels, and thus are considered 
more effective than lowering the sound level limits.” - KTM AG 

“We  believe  the  other  way  around  is  appropriate:  in-use controls  will  reduce  the  amount  of 
aftermarket mufflers/ tampering/ … and thus improving real world noise. Setting lower sound 
level limits only, without enforcement, will not have effect.” - 

Honda 

“If you do no not a high number of road side checks, the manipulations of OEM- silencers or 
the use of not approved replacement silencers or manipulated replacement silencers will have 
a higher influence in the negative way than the Sound Pressure Level reduction will have it in 
the positive way.” - Ministry of Transport and digital Infrastructure of Germany (BMVI) 

“The  excessive  sound  emission  levels  are  the  main  annoyance  of  people.  Those  sound 
emissions will not be tackled with a lowered sound emission level limit alone. The chance of 
being checked during in-service (by market surveillance and possibly PTI), in combination with 
high fines will result in less tampering. There should however be a proper way to perform these 
in-service checks.” - RDW 

“This is linked to the ageing and use of the vehicle.” - Ministry of ecological transition 

“Rare  and  poor  controls  are  a  problem,  as  are  compliant  requirements  for  replacement 
exhausts.” - Individual 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles.” - Ministry of transport and Construction of the Slovak republic 

“In-use control will tend to reveal lower noise improvement levels than those in the regulation” 
- IDIADA 

“More effective enforcement/in-use controls based on current sound level limits would already 
translate into an improvement of real-world sound emission levels” - IMMA 

“We expect more improvement from enforcing current regulations.” - Kawasaki Motors Europe 
N.V. 

Conclusions 

From  the  received  answers  the  general  trend  is  that  most  stakeholders  think  that  lowering 
sound  emission  level  limits  would  not  translate  into  a significant  improvement  of  the  sound 
emission level values collected through in-use controls. The “no improvement” option is the 
most popular, followed by the “medium improvement”. 

76 

 
1.2.30. Question No 30 - In your opinion, which bodies should be in 
charge of the in-use control of sound emission levels on the 
existing fleet of L-category vehicles? 

Options:  Local  traffic  and  law  enforcement  authorities,  national  traffic  and  law  enforcement 
authorities, periodical technical inspection authorities, approval authorities, other 

Figure 34: Answers to question 30 

Answers received as other 

Assurance companies; market surveillance. 

Additional comments 

"A more realistic ASEP, Enforcement in combination with measures to change the culture with 
certain groups of riders and drivers are the only ways to solve the noise annoyance problem. 

We excluded Periodical Technical Inspection authorities because it is quite easy to temporary 
replace a silencer that is not according to legal requirements with the original silencer. This is 
already common practice in countries with PTI for motorcycles." – FEMA 

“La modificación de los sistemas de escape en las motocicletas es muy habitual y se puede 
realizar muy rápidamente. Esto impide que la ITV periódica pueda realizar un control eficiente 
de  los  vehículos  puesto  que  los  muchos  titulares  acudirán  a  la  inspección  cumpliendo  las 
condiciones de homologación, pero circularan incumpliéndolas.” - Ayuntamiento de Madrid 

“Local authorities know best where to control and where it isn't worth to do so.” - Swiss Federal 
Roads Office (FEDRO) 

"In-use controls need to be aware of type approval Regulation and local Regulation. Persons 
need also to be equipped with measurement devices and acceptable place. Not easy to meet 
all these requirements. 

Approval Authorities have a big concern here and market surveillance could be the good way 
to check replacement devices and tampering. Regulation 92 maybe need an update..." - UTAC 
CERAM 

“In  Norway  today,  it  is  the  national  approval  authorities  and  the  national  traffic  and  law 
enforcement  authorities  who  perform  in-use  control  of  L-category  vehicles.  The  number  of 
performed controls will always be  subject to the resource  capacity.” - 

Norwegian Public Roads Administration 

 
 
 
"Local  enforcement  will  reduce  the  amount  of  tampered/illegally  modified  vehicles  in  the 
market. 

PTI will be able to identify those vehicles not in line with their approved specifications. 

Approval authorities need to do market surveillance activities." - ACEM 

“We believe the implementation of level controls will reduce the amount of illegally tampered 
vehicles in the market. Also, Approval Authorities should carry out surveillance activities on the 
vehicle fleet.” - MV Agusta Motor S.p.A. 

"Local  enforcement  will  reduce  the  amount  of  tampered/illegally  modified  vehicles  in  the 
market. 

PTI will be able to identify those vehicles not in line with their approved specifications. Approval 
authorities need to do market surveillance activities." - Ducati Motor Holding 

“In  use  compliance  remains  the  main  issue,  not  the  type  approval  limits.  PTI  has  not  been 
shown  to  be  effective  in  the  countries  where  it  exists.”  -  Federation  Internationale  de 
Motocyclisme 

“Local  enforcement  will  reduce  the  amount  of  tampered/illegally  modified  vehicles  in  the 
market. PTI will be able to identify those vehicles not in line with their approved specifications. 
Roadside enforcement will have a positive effect on riders’ behaviour. 

Approval authorities need to do market surveillance activities.” - KTM AG 

“Local  enforcement  will  reduce  the  amount  of  tampered/illegally  modified  vehicles  in  the 
market. PTI will be able to identify those vehicles not in line with their approved specifications. 
Approval authorities need to do market surveillance activities.” – Honda 

"Local  and  national  traffic  and  law  enforcement  authorities  for  roadside  checks  (SPL- 
measuremets  and  checking  the  high  temperature  resistant  Stickers  on  approved  silencers 
given by PTI-authorities or assurance companies). 

Market surveillance authorities for the vehicle and products in the market. Approval authorities 
for Cop. 

PTI-authorities or assurance companies for ""marking approved silencers in use for example 
by  high  temperature  resistant  Stickers""  every  2  years."  -  Ministry  of  Transport  and  digital 
Infrastructure of Germany (BMVI) 

"A correct and easy enforcement protocol will deal with the excessive sound emissions which 
are the main annoyance of the people. The risk of getting high fines will result in lower sound 
emissions overall. 

Also,  the  possibility  to  refuse  vehicles  with  a  registration  certificate  (Directive  1999/37/EC) 
based on a foreign individual of national type approval without knowing the foreign national 
regulations, mounted mufflers and sound level performances at the time of approval." - RDW 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles.” - Ministry of transport and Construction of the Slovak republic 

“Periodic  control  in  ITV  +  random  control  by  law  enforcement  authorities  if  appropriate.”  - 
IDIADA 

“Local  enforcement  will  reduce  the  amount  of  tampered/illegally  modified  vehicles  in  the 
market. PTI will be able to identify those vehicles not in line with their approved specifications. 
Approval authorities need to do market surveillance activities.” - IMMA 

“Subject  to  correct  training  and  equipment  being  utilised  in  the  testing  process  by  the 
authorities concerned.” - Triumph Motorcycles 

78 

 
 
Conclusions 

There aren’t clear trends on the understanding of which bodies should be in charge of the in-
use control of sound emission levels on the existing fleet of L-category vehicles. Local traffic 
and  law  enforcement  authorities  are  understood  as  the  most  indicated,  and  approval 
authorities  are  understood  as  the  least  indicated  to  do  this  task,  but  differences  are  not 
substantial because opinions are evenly distributed. 

1.2.31. Additional remarks and comments 

“We have doubted if we should cooperate to this survey because of the quality of the questions 
and a feeling that a number of them were steering. For this reason, we will monitor the follow-
up with extreme caution.” – FEMA 

“As  a motorcyclist  I  am  interested  not  to  become  an  "outlaw"  just  because motorcycles are 
seen as harmful, loud and "bad". Motorcycles can contribute to solve the congestion problem 
in  our  cities,  but  they  have  also  to  be  environmentally  compatible.”  -  Swiss  Federal  Roads 
Office (FEDRO) 

"First of all, this is a serious survey! Thanks. 

But, you should separate concerned L-cat for several questions. 

I'm surprised that nobody asks within this survey for Regulation UN ECE 92. This is a key point 
for noise pollution." - UTAC CERAM 

“The noise  that  annoys  the  public  the  most  occurs  while  the  engine  accelerates,  especially 
with the motorcycle or moped stopped, and this is not checked either in the test procedures or 
on the ITV - Applus+ 

"The  noise that  annoys  the  public  the most  occurs  while the  engine accelerates,  especially 
with the bike stopped, and this is not checked either in the test procedures or on the ITV. 

The solution to reduce general environmental noise is not to lower the limit values again, but 
to ensure that all vehicles that circulate meet the current ones." - Applus+ 

Automotive 

“Note: Some questions were unanswered from ACEM side as these are manufacturer specific. 
Some of these questions are subjected to anti-trust rules. – ACEM 

"The noise pollution issue can be divided into two aspects: 

One is the environmental noise as represented by Leq and LDEN. 

The  other  is  a  sudden  noise,  what  we  call  ""single  event  noise"",  which  constitutes  the 
causation of noise disturbances. 

Because L-category vehicles have a lower proportion of traffic flow and hence the impact of 
their  sound  emission  levels  on  environmental  noise  is  relatively  low,  our  recognition  is  that 
complaints on noise disturbance caused by sudden noises are under controversy. 

According  to  the  2017  EC  report,  it  would  take  approx.  10  years  before  a  change  in  type 
approval limits starts to produce an effect in consideration of a period required for replacement 
of vehicles in the market from those type approved under the conventional limits with the new 
ones. 

In  addition,  it  is  generally  considered  illegally  tampered  mufflers  and  aggressive  driving 
behaviors constitute the majority of causations of such sudden noises. 

Therefore, we hope that this EC study would include thorough discussions about how effective 
lowering the type approval limits for OEM vehicles would be to reduce sudden noises and why; 
or otherwise whether there could be any other effective measures." - Yamaha Motor Co., Ltd. 

 
 
"no additional comments. Thanks" - Honda 

"It is necessary to improve UN Regulation no. 92, as follows: 

- 
clearly  prescribe  the  content  of  the  replacement  exhaust  system  manufacturer's 
certificate, the content of which should clearly describe the variant and design of the motorcycle 
on which the replacement exhaust system may be installed, a description of all parts forming 
the replacement exhaust system, a note on the installation of one or two or more mufflers; 

- 
disable the preparatory elements on the replacement silencer for easy removal of the 
dB killer and increase the responsibility of the constructor for easy unauthorized modification 
(prohibition of the construction of the final dB killer secured by a small weld, easily removable 
rivet or safety ring); 

and most important of all in UN Regulation no. 92 include the obligation to use noise 

- 
testing from UN Regulation no. 41.04 for Euro 4 and Euro 5 motorcycles. 

The persons responsible for checking the correctness and originality of the exhaust systems 
must be adequately trained." - Individual 

“Ministry of transport and construction of the Slovak republic have no experience in test and 
approving L-category vehicles.” - Ministry of transport and Construction of the Slovak republic 

“Was interesting, thanks! =)” - Anonymous 

1.2.32. General conclusions 

L5e, L6e and L7e are categories of vehicles for which general public knowledge is lower than 
the  knowledge  on  L3  category  probably  due  to  the  small  percentage  of  these  units  among 
vehicle’s  fleet.  Many  answers  are  focused  on  L3e  motorcycles  and  express  a  lack  of 
information or criteria on the rest of L-category vehicles targeted by this study. 

Motorcycles are understood as the vehicles more prone to be tampered and thus identified as 
the ones producing the highest noise annoyance on public roads. 

Tampering, and in particular fitting of NORESS is seen as having a significant impact on the 
motorcycle noise perception. 

Single  noise  events  (e.g.  aggressive  driving)  are  also  frequently  pointed  out  as  a  major 
contributor to people annoyance. 

There  are  some  references  to  improve  UN  Regulation  no.  92  in  order  to  ensure  more 
comprehensive homologation procedures for replacement exhaust systems. 

Regarding  the  regulatory  sound  level  test  procedures  there  are  often  references  to  the 
oncoming UNECE R41.05 ASEP prescriptions as a positive move in order to make a more 
representative assessment of the sound level generated in a wider driving scenarios spectrum. 

When asked about a possible reduction of sound emissions level limits, most of the answers 
agree  that  in-use  controls,  such  as:  local  traffic  controls,  law  enforcement  authorities  and 
periodical  technical  inspection  authorities,  would  be  the  most  efficient  way  to  detect  non-
conforming vehicles and thus lowering effectively the noise emission caused by motorcycles 
in the urban and extra-urban areas. 

According  to  the  obtained  results,  the  vast  majority  of  stakeholders  think  that  the  L3e-  A3 
vehicles are ones for which it is more difficult to comply with the current sound level limits. 

Keeping the sound emission level limits unchanged for two-wheelers is a common trend among 
the stakeholders’ answers. For tricycles and quadricycles category vehicles there are opposite 
opinions: a significant percentage of answers is against a change of the limits, but there is also 
a non-negligible part of the opinions in the sense of a reduction of the sound level limits up to 
over 2 dB (A). 

80 

 
1.3. Literature review 

Task 1.2 in the previous section identifies the potential of the implementation of current and 
future technologies by reviewing the powertrain and ancillary systems technology addressing 
vehicle  noise  reduction.  A  wide  range  of  technical  literature  has  been  reviewed  in  order  to 
present the information in the task. The content in this section is useful to define a framework 
when preparing the high-level proposal for future noise level emissions 

1.3.1. Vehicle life expectancy 

The average age of road vehicles in Europe has increased since 2000. In 2014, the average 
age of passenger cars was 7.4 years, 8 % older than that of the average fleet in 2000. For 
other vehicle types, the average age was 8.4 years for vans, 8.1 years for heavy duty vehicles, 
9.1 years for two-wheelers, and 9.4 years for buses. 

The age of two-wheel vehicles increased from 8.9 to 9 years over the same period, reaching 
its  peak  in  2004,  with  an  average  age  of  9.5  years.  The  average  age  of  buses  has  also 
increased, from an average of 8.7 years in 2000 to 9.4 years in 2014. 

Figure 35: Average age if road vehicles (from reference https://www.eea.europa.eu/data-and- maps/indicators/average-age-of-
the-vehicle-fleet/average-age-of-the-vehicle) 

1.3.2. Considerations  on  noise  control  technology  for  powertrain 

noise reduction in l-type vehicles 

The majority of motorcycle engines are configured as singles, parallel twins, triples, fours and 
sixes; and all these may be inline or transverse. Vee engines include V-twins and V-fours, and 
horizontally opposed engines include flat-twins, flat-fours and flat- sixes. Wankel engines are 
either single-rotor or twin-rotor. Bigger bikes tend to have more cylinders for smoothness and 
increased power. Modern singles range in capacity from 50 cc to 660 cc, twins from 175 cc to 
1800 cc, triples from 380 cc to 2,300 cc, and so on. 

The major noise contributing source of L-type vehicles is normally the powertrain system. From 
a noise radiation point of view this includes the engine block and the cylinders, gear box, the 
intake and the exhaust system, being the exhaust a major contributor to noise. 

 
 
 
 
The  intrinsic  noise  generation  mechanism  is  combustion  and  mechanical  related.  Thus,  we 
can assume that the total noise produced by motorcycle internal combustion engines can be 
broken down in combustion and mechanical noise. 

The combustion noise component is produced by the time development of the firing cycles in 
the combustion chambers and it is attenuated by the engine block and the wall cylinders. This 
part  of  the  noise  is  related  to  the  number  of  explosions  per  crank-  shaft  rotation,  and  the 
pressure produced by the ignition of the air-fuel mixture. The mechanical noise component of 
the  engine  noise  is  caused  by  the  impacts  produced  by  the  various  mobile  engines 
components when the mechanical plays are taken up by the connecting rod, the cam-shaft, 
the valve cams and the valves. This noise component is also associated to the valve timing 
and their movement pattern defined by their high accelerations experienced when opening and 
closing. 

We  note  that  noise  is  generated  by  vibrating  sources  or  by  high  pressure  (or  rarefactions) 
pulses generated at the outlet or inlet of a flow pipe, respectively. Therefore, designs oriented 
to reduce these wall surface vibrations or gas pulsations, will eventually be associated to a 
noise reduction. In this  line  of  action, general  design concepts  that tend to produce  a quiet 
engine are: 

•  Use of secondary engine balances. 

• 

Increase engine mass and stiffness. Note that this is negative for emissions and vehicle 
performance. Also, the market demands more vehicle power, bigger and heavier pistons 
and higher r.p.m which produces more vibrations. 

•  Use engine rubber mounts. This reduces vehicle vibration but reduces chassis stiffness. 

•  Use self-balancing engines that use the engine block as part of the chassis stiffness. Note 
that  some  engine  configurations  such  as,  in  line-six,  flat  engines,  are  inherently  self-
balancing,  smoother  and 
less  noisy  (per  comparative  power).Particular  engine 
configurations (V-Twin, for example) can be allowed to orbit (as a rigid body) on mounts 
that  permit  this  type  of  movement,  while  retaining  stiffness  in  twist  direction  and 
participation with the chassis. 

•  Provide engine vibration cancellation in the form of balance shafts or other means (such 

as dummy balance pistons). 

•  Control  engine  block  vibration  modes:  global  and  local.  We  note  that  vibration  modes 

increase the radiated noise at the corresponding natural frequencies. 

•  Combustion  control:  This  implies  controlling  the  evolution  of  the  combustion  pressure 
development  during  the  mixture  burning.  Valve  timing,  injection  distribution  and  ignition 
affect the combustion control. 

Cylinder valve control in motorcycle four-strokes engines 

Cylinder valve control is of paramount importance to guarantee the correct timing. This has a 
direct impact on engine power and emissions, as well as in combustion noise. 

The most important systems in use to implement valve control are: 

Overhead valves (OHV) 

In a side-valve engine, the valves are operated from the under head without special valve gear. 
Overhead valve (OHV) engines have valves operated by pushrods. 

Overhead cam (SOHC) and Double overhead cam 

Single and double-overhead camshaft (SOHC and DOHC) have overhead cam-shafts typically 
operated by chain, belt gear train or bevel gear drive. These driving systems exhibit different 
mechanical noise characteristic that depend on the engine speed and the mechanical plays 

82 

 
REV system 

This system enables the switching over the number of valve operations per cylinder between 
low and medium speed range and high speed revolution range. 

Hyper VTEC and VVT systems 

The VTEC system is very effective to improve the volumetric efficiency of four stroke internal 
combustion engines, resulting in a high performance at high r.p.m and lower fuel consumption 
at low rpm. The VTEC uses two camshaft profiles and hydraulically select between profiles. It 
is different from the standard VVT (Variable valve timing) system which changes only the valve 
timing and does not change the camshaft profile or valve lift in any way. 

Desmodronic system 

In this type of system the valves are closed by a cam and leverage system, rather than by a 
conventional spring. The main benefit of the system is the prevention of valve float at high rpm. 
This system does not have to overcome the force of the spring. 

Asymmetrical cam profile 

At high speeds (in terms of r.p.m.) engines can employ asymmetrical cam profiles in order to 
quickly  open  valves  and  set  them  back  in  their  seats  more  gently  to  reduce  wear.  An 
asymmetric cam either opens or closes the valves more slowly than it could ensuring a more 
controlled acceleration of the combined mass of the reciprocating components, the valve, the 
tappets and the springs. 

Nested springs 

These  are  used  to  reduce  valve  oscillations.  Various  springs  can  be  nested  not to produce 
more force on the valve, since the inner ones have no significant contribution, but to act as 
snubbers to reduce oscillations in the outer spring 

Use of progressive springs 

Progressive  springs  do  not  resonate  in  the  frequency  band  of  engine  rpm  excitation.  To 
achieve this effect these springs are wound with varying pitch or varying diameter. 

Motorcycle engine cam drive systems 

The transmission between the crank-shat rotations to the camshaft can be carried out using 
gears, chassis or belts, depending on the required engine performance. 

Using compact rigid spur gears all the way from the crankshaft to the camshaft as in racing 
engines is expensive and presents technical problems. It is kwon that aluminium, of which the 
engines are normally made, expands with heat about three times more than does the steal of 
which gears are made. Therefore, as a cold engine warms up to operating temperature tooth-
to-tooth gear backlash increases in gear cam drives. 

A way around this is to mount gears in a steel frame keeping the backlash constant but the 
engine temperature expansion has to be dealt with. Gear backlash in the final mesh can be 
limited by employing a scissors gear. This is a gear that is actually two half-thickness gears, 
carrying spring that cause their teeth to spread out like so many little scissors, therefore taking 
up the clearance and mostly eliminating noise. 

One way to avoid this problem is to use tooth belts, which are effective because they reduce 
costs  and  are  quiet  and  reliable.  For  race  engines  the  load  on  the  belt  is  high,  the  valves 
duration has to be reduced in the interest of mid-range accelerations and valve lift has to be 
increased to compensate for the reduction in open time. Also the valves acceleration is very 
high. This is difficult to achieve with belts. In this case steel- chains can be useful. Today, cam 
drive by silent chain is the majority solution. It is compact inexpensive and quiet. 

 
 
Exhaust systems 

Exhaust  silencers  are  design  to  suppress  to  an  acceptable  level  the  noise  created  by  the 
exhaust  gases  expelled  from  the  engine  cylinders.  Exhaust  noise  is  due  to  pressure  wave 
vibrations produced by sudden and periodic release of energy through the exhaust ports. The 
exhaust system must suppress two basic types of noise. 

An  exhaust  system  is  usually  piping  used  to  guide  reaction  exhaust  gases  away  from  a 
controlled  combustion  inside  an  engine.  The  entire  system  conveys  burnt  gases  from  the 
engine and includes one or more exhaust pipes. Depending on the overall system design, the 
exhaust gas may flow through one or more of: 

•  A cylinder head and exhaust manifold. 

•  A turbocharger to increase engine power. 

•  A catalytic converter to reduce air pollution. 

In most motorcycles all or most of the exhaust system is visible and may be chrome plated as 
a  display  feature.  Aftermarket  exhausts  may  be  made  from  steel,  aluminium,  titanium,  or 
carbon fibre. 

Motorcycle exhausts come in many varieties depending on the type of engine and its intended 
use.  A  twin  cylinder  bike  may  have  independent  exhaust  sections,  or  alternatively  a  single 
exhaust  section  known  as  a  two-into-one  (2-1).  Four  cylinder  machines,  super-sport  bikes, 
often have a twin exhaust system. 

The original equipment mufflers typically reduce the noise level from the tailpipe by bouncing 
sound waves off of the back, front, and sides of the muffler. They are designed to meet the 
maximum allowable noise level required by government regulations, however some original 
equipment mufflers are a significant source of back pressure. 

Glasspack  mufflers  (also  called  'cannons'  or  'hotdogs')  are  straight-through  design  mufflers 
which consist of an inner perforated tube, an outer solid tube and fibreglass sound insulation 
between the two tubes. They often have less back pressure than original equipment mufflers, 
but are relatively ineffective at reducing sound levels. 

Another  common  type  of  muffler  is  the  chambered  muffler,  which  consists  of  a  series  of 
concentric or eccentric pipes inside the expansion chamber cavity. These pipes allow sound 
to travel into them and cause the sound waves to bounce off the closed, flat, ends of the pipe. 
These reflections partially cancel each other out, reducing the sound level. 

Resonators are sections of pipe that expand to a larger diameter and allow the sound waves 
to reflect off the walls and cancel out, therefore reducing the noise level. 

Resonators  can  be  used  inside  mufflers,  or  also  as  separate  components  in  an  exhaust 
system. 

Fundamental noise 

This  noise  results  from  the  release  of  compressed  products  of  combustion  every  time  the 
exhaust  valve  is  opened.  The  fundamental  frequency  of  the  exhaust  noise  depends  on  the 
engine’s  speed  and  the  basic  requirement  of  the  silencer  is  to  dissipate  the  energy  of  the 
resulting shock waves 

Secondary noise 

Movement of gas within the exhaust silencer casing can be responsible for various crackles or 
rasps and can be the cause of the end plates of the chambers or the chambers themselves 
rattling. Uneven firing pulses often exaggerate these noises. Cylinder-to-cylinder and stroke-
to-stroke  variation  can  also  be  responsible  for  promoting  subharmonics  at  different 
frequencies. 

84 

 
Noise suppression strategies in exhaust systems 

Exhaust gas noise suppression can be achieved by applying three different methods: 

• 

• 

• 

Resonance chamber damping 

Reactive interference chamber damping 

Absorption material chamber damping 

Most  modern  exhaust  silencers  utilise  a  combination  of  two  or  even  all  three  methods  of 
reducing  the  level  of  exhaust  gas  noise.  The  complete  exhaust  system  should  have  the 
minimum of back pressure so that it will absorb no more that say 5% of engine’s power. 

Resonant chamber silencer 

The  cavity  resonator  method  of  sound  suppression  adopts  the  principle  of  a  Helmholtz 
resonator.  The  resonator  chambers  have  different  gas  volume  capacities  and  surround  a 
central perforated straight-through tube. A perforated narrow-neck hole along the tube connect 
the resonating-chambers to the passing through exhaust. As the exhaust gas sound-waves 
travel along the straight-through tube, the pulsating exhaust gas flow at the entrance to each 
resonator chamber creates a pressure variation within these chambers. When the excitation 
frequency  carried  by  the  exhaust  gas  due  to  the  engine  firing  frequency  coincides  with  the 
resonance frequency of the cavity resonator, the acoustic wave is attenuated due to the energy 
dissipation occurring in the resonator. 

This approach is a very selective low-frequency narrow-band noise absorber. It is possible to 
combine several of these resonator in series on a piping system so that not only each cancel 
out  its  own  resonant  frequency,  but  they  can  be  made  to  overlap  so  that  sound  energy  is 
attenuated over a wide range instead at sharply tuned points. 

Reactive interference silencer 

The reactive interference method of sound suppression adopts the principle of a Quincke tube. 
The simplest form of reactive interference silencer is a straight-through central tube with twin 
short parallel side branch tubes supported by two baffle-plates set slightly in from the end-caps 
to form separated expansion chambers. 

Absorptive chamber silencer 

With  the  absorptive  or  dissipative  method  of  sound  suppression  the  sound  waves  are 
dissipated by means of acoustically dead material which is able to absorb a large portion of 
the outgoing exhaust-gas. This material must be heat-resistant such as fiber gas, long-fiber 
mineral wool such as basalt or rock-wool and wire-wool. These materials are soft, flexible and 
provide a cellular structural mesh of interlocking pores. Such materials take in rapidly the sound 
wave impulses and causes the material’s fibers to move, thus converting sound energy into 
mechanical vibration and heat. The construction of the simplest single pass straight-through 
absorptive  silencer  consists  of  mineral-wool  or  something  similar  packed  into  the  annular 
space between a perforated central tube and the outer cylindrical steel sheet casing. 

Intake systems 

To make more power, air-boxes generally need to be larger, both in volume around the intakes 
and in the space taken up by devices such as ram-air ducts. More power means more intake 
air,  which  means  more  intake  noise.  But  the  air-box  is  generally  surrounded  by  frame  and 
bodywork  components.  Often  the  fuel  tank  covers  the  air-  box  and  the  nose  of  the  fairing 
incorporates the ram-air system, so there are double walls and surfaces that can be used to 
deflect and absorb sound. Increasing the volume while decreasing the noise emitted by the 
intake is a challenging problem when the space available is limited. 

 
 
Intake noise is generated by the pressure fluctuation due to the intake valves and the air flow 
entering the duct at high speed. Intake noise can be reduced by proper design of the following 
components: 

•  Air flow path 

• 

• 

Inlet cross-section geometry 

Inlet end pipe design 

•  Air filter implementation 

•  Adaptation of Helmholtz resonators in the intake system 

•  Non resonant behaviour of intake casing 

1.3.3. Vehicle  average  mileage  (per  category)  –  (information  from 

year 2015)  

Table 1 below shows the annual mileage carried out with motorcycles in Europe. 

Table 1: Mileage per year run per L-vehicles 

The  EU  sample  shows  that  average  mileage  by  PTW  is  generally  between  3,000  and 
10,000km/year. 

A country comparison shows that there is not a specific geographical trend: 

• 

In Sweden, the largest group of riders (24.3% of our respondents) rides between 1,000 to 
3,000km a year. 

•  The  largest  group  of  riders  in  the  Czech  Republic  (26.6%  of  respondents),  Germany 
(22.6%),  Portugal  (19.9%)  and  the  United  Kingdom  (22.3%)  ride  between  3,001  and 
5,000km a year. 

•  The largest group of riders in Denmark (20.3% of respondents), Finland (20.8%), Greece 
(23.1%),  Italy  (20.6%), Spain  (20.1%)  and Switzerland  (22.1%)  ride  between 7,001 and 
10,000km a year. 

•  The largest group of riders in Belgium (23.1% of respondents), France (20.7%) and Norway 

(21.1%) ride between 10,001 and 15,000km a year. 

• 

In  the  Netherlands,  the  largest  group  of  riders  (22.3%  of  respondents)  rides  more  than 
15,000km a year. 

86 

 
 
 
1.3.4. Extra information/graphs 

Vehicle use – Number of motorcycles by rider 

Table 2: Mileage per year run per L-vehicles 

The  European  dataset  shows  that  the  vast  majority  of  riders  own  just  one  powered  two-
wheeler.  However,  geographical  differences  can  be  observed.  Motorcyclists  from  Southern 
European countries tend to own just one PTW, as is the case in France (68.6%), Spain (68.1%) 
and  Portugal  (67.9%).  By  contrast,  riders  from  Northern  European  countries  tend  to  own 
several bikes. Riders from Norway, Sweden and Switzerland owned the highest number, with 
9.2%, 9.6% and 9.6% of them respectively owning more than 3 powered two wheelers. 

Engine size 

The European dataset shows that the majority of bikes owned have engine sizes exceeding 
400 cm3, with a reasonably equal share between bikes above 400 cm3, above 700 cm3, and 
above  1000  cm3.  Table  3,  presents  the  percentage  distribution  of  the  engine  size  of 
motorbikes.  Note  that  the  engine  size  is  ordered  so  that  the  corresponding  percentage  is 
shown from the highest to the smallest value. 

Table 3: Percentage distribution of engine size 

A national analysis within the EU shows that: 

•  The Czech Republic is the country with the largest number of PTWs with an engine size 
below  125  cm3  (16.8%).  This  smallest  engine  size  is  least  represented  in  Switzerland, 
where such PTWs constitute just 2% of all PTWs owned by respondents. 

•  Greece has the highest number of 125-400 cm3 PTWs (representing 29.2% of all PTWs). 

 
 
 
 
•  401-700 cm3 is the most popular engine size in France, Portugal and Spain. In Portugal, 

37.4% of PTWs have this engine size. 

•  701-1000 cm3 is the most popular engine size in Germany, Italy, though the Netherlands 

has the highest percentage of this engine size (32.2% of PTWs). 

•  Finally,  motorcycles  exceeding  1000  cm3  are  the  most  popular  in  Belgium,  Denmark, 
Finland,  the  Netherlands,  Norway,  Sweden,  Switzerland  and  the  United  Kingdom.  In 
Belgium, motorcycles exceeding 1000 cm3 represent 45.3% of all PTWs. 

• 

It  should  be  noted  that  the  breakdown  of  engine  size  is  quite  homogeneous  in  Czech 
Republic. By contrast, the breakdown in Belgium is quite unbalanced, with 3 engine size 
representing more than 88% of PTWs owned by respondents. Moreover, the most popular 
engine size accounts for approximately 45% of vehicles, while the second most popular 
size accounts for just 22%. 

Type of vehicle 

Table 4: Distribution vehicle type 

The  preferred  type  of  vehicle  varies  greatly  from  one  country  to  another  without  any  real 
geographical  trend:  Standard  motorcycles  are  the  most  popular  type  of  PTW  in  the  Czech 
Republic,  France  (33.3%),  Germany,  Italy,  Portugal  and  Switzerland.  Sport  Touring 
motorcycles are the most popular type in Denmark, the Netherlands, Norway, Spain and the 
United Kingdom. In Denmark, they account for 32.7% of all PTWs. On/off road bikes are the 
most  popular  type  in  Greece  and  Sweden.  In  Greece,  they  represent  30.7%  of  all  PTWs. 
Touring  bikes  are the most  popular type  in Belgium, representing  24.1%  of  PTWs.  Custom 
bikes  are  the  most  popular  type  in  Finland,  representing  21.1%  of  PTWs.  Greece  has  the 
highest rate of scooters (27.7%) and electric (0.5%) PTWs declared by survey respondents. 

Riding habits 

88 

 
 
 
Another riding characteristic that affects the noise impact of L category vehicles as a set is the 
whether these vehicles tend to be used as part of bigger groups or in isolation. 

Table 5: Distribution of ‘Riding habits’ 

The vast majority of riders in Europe generally ride alone (67.8%), while a tiny minority rides 
in groups of over 10 riders (1.7%). 

A country analysis further illustrates that group (>10) riding is more common in Denmark where 
6.6%  of  riders  ride  most  of  the  time  with  many  other  motorcyclists,  followed  by  Belgium  at 
4.1%. For the other selected countries, this proportion drops below 3%. 

Vehicle use indensity 

As expected, L-category vehicle use in Europe is clearly related to the corresponding weather 
characteristics of the countries. Mild temperatures, longer period of day light boosts the use of 
these vehicles. 

Table 6: Distribution of ‘vehicle use intensity’ 

A national comparison tells us that the countries where riders use their PTW every day (Greece 
(73.4%),  Spain  (37.4%),  Portugal  (37.2%)  and  Italy  (32.1%)  )  are  all  Southern  European 
countries, where weather conditions are mild enough to allow riding throughout the year. This 
is  also in  line  with the fact  that  Greece,  Portugal  and  Spain have the  highest  rates  of  PTW 
commuting. It should also be noted that Greece has the highest percentage of scooters  – a 
typical urban vehicle – among the PTWs owned by respondents. 

Countries  where  riders  use  their  PTW  only  during  the  summer  (Norway  (80.2%),  Denmark 
(73.0%), Sweden (70.4%) and Finland (69.1%)) are logically Nordic countries where weather 
conditions make riding difficult outside summer. 

 
 
 
 
1.3.5. Registrations per country and per vehicle category 

It  is  important  to  know  the  number  of  registrations  of  L-category  vehicles  in  Europe,  to 
understand which is the current balance between electric and ICE motorcycles. 

Furthermore, the data included in this point can provide us information regarding the evolution 
of the electric vehicles fleet in the European market. 

2018 vs 2019 registrations of motorcycles and mopeds in the EU. Internal combustion 
engine + Electric vehicles. 

Period 

Jan - Dec 

Year  Motorcycles  Mopeds 
999.868  272.338 
2018 
1.079.524  303.152 
2019 

Figure 36: Cummulative registration of motorcycles and mopeds in the EU (ICE+EV) 

Registrations  of  mopeds,  motorcycles  and  quadricycles  in  the  EU.  Only  electric 
vehicles 

Period 

Jan - Dec 

Year  Mopeds  Motorcycles  Quadricycles 
3.184 
2018 
2.816 
2019 

39.940 
59.776 

6.901 
14.111 

90 

  
 
 
 
 
 
 
 
Figure 37: Registrations of mopeds, motorcycles and quadricycles in the EU (EV only) 

2019 vs 2020 registrations of motorcycles in the EU. Internal combustion engines. 

 
 
 
 
 
Figure 38: Registrations of motorcycles in the EU (ICE) 

2019 vs 2020 registrations of motorcycles in the EU. Only electric vehicles. 

Figure 39: Registrations of motorcycles in the EU (EV only) 

92 

Row Labels  Motorcycles (2019) Motorcycles (2020) January 309 614 February 795 1.067 March 771 1.326 April 631 387 May 640 2.428 June 1.672 1.262 Grand Total 4.818 7.084   
 
 
 
 
 
 
 
 
 
 
 
 
2018 vs 2019 % of electric motorcycles 

1st semester 2019 vs 1st semester 2020 % of electric motorcycles 

Figure 40: 

Figure 41 

1.3.6. Average speed in EU cities (information from year 2007) 

Study performed measuring a GPS average speed of a car in a limited area of 40 kms2 nearer 
to the centre of the city between June and September. This information is useful to have an 
overall view of the average speeds in EU cities. 

Find below the average speed of cars in the main EU cities (km/h): 

Table 7: Average speed of cars in EU cities 

(Ref: https://www.motorpasion.com/otros/las-ciudades-europeas-con-el-trafico-mas-lento) 

City 
London 
Berlin 
Warsaw 
Manchester 
Edinburgh 
Rome 
Glasgow 
Bristol 
Paris 

Average speed (km/h) 
19 
24 
26 
28 
30 
30 
30 
30 
32 

 
 
 
 
 
 
 
 
Belfast 
Munich 
Amsterdam 
Dublin 
Birmingham 
Barcelona 
Prague 
Leeds 
Cardiff 
Newcastle 
Vienna 
Lyon 
Turin 
Milan 
Madrid 
Brussels 
Colonia 
Rotterdam 
Frankfurt 
Ginebra 
Hamburg 

32 
32 
34 
35 
30 
35 
37 
37 
39 
42 
46 
46 
51 
51 
51 
56 
58 
66 
68 
71 
84 

1.3.7. Speed limits EU cities: (information from year 2015) 

We note that the information in sections 1.3.5 and 1.3.6 seems dispersed in years 2007 and 
2015 and away from the timing of the data available in sections 5, 6 and 9 – years 2018 and 
2020. The reason for this is that it was possible to find more recent information for sections 7 
and 8. 

Table 8: Speed limits in EU cities  

(Ref: https://www.motor.mapfre.es/consejos-practicos/seguridad-vial/todos-los-limites-de-
velocidad-en- europa/) 

Street 

Spain 
Slovenia 
Portugal 
Belgium 
Ireland 
France 
Italy 
Croatia 
Slovakia 
Luxembourg 
Romania 
Czech Republic 
Hungary 
Greece 
Estonia 
Finland 
Norway 
Germany 
Austria 
Holland 
Denmark 
Bulgary 

50 
30 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 

Non-urban road without 
shoulder 
90 
90 
90 
80 
80 
90 
90 
90 
90 
90 
90 
90 
90 
90 
90 
80 
80 
100 
100 
80 
80 
90 

km/h 

Non-urban road with 
shoulder (< 1,5 m) 
90 
90 
90 
80 
80 
90 
90 
90 
90 
90 
90 
90 
90 
90 
90 
80 
80 
100 
100 
80 
80 
90 

94 

Non-urban road with 
shoulder (> 1,5 m) 
100 
90 
90 
80 
80 
90 
90 
90 
90 
90 
90 
90 
90 
90 
90 
80 
80 
100 
100 
80 
80 
90 

Motorway or dual 
carriageway 
120 
120 
120 
120 
120 
130 
130 
130 
130 
130 
130 
130 
130 
130 
90 (110*) 
80, 100 or 120** 
100 
130 
130 
130 
130 
140 

 
 
Poland 
50 
United Kingdom  48 
50 
Switzerland 
30 
Cyprus 
50 
Sweden 
50 
Latvia 

100 
96 
80 
80 
70 
90 

100 
96 
80 
80 
70 
90 

100 
96 
80 
80 
70 
90 

120/140 
112 
100 
100 
110 
80 

1.3.8. Number of EU cities with low speed areas (information from 

year 2019) 

The European cities with 30km/h limit are listed below: 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

Dublin 

London 

Paris 

Lyon 

Milan 

Rome 

Brussels 

Vienna 

Berlin 

Copenhagen 

Stockholm 

Lodz 

Helsinki 

Spanish cities with 30 km/h limit: 

Pontevedra 

Salamanca 

Oviedo 

Bilbao 

Burgos 

Pamplona 

Soria 

Zaragoza 

Barcelona 

Palma 

Madrid 

Cuenca 

Valencia 

Cordoba 

Sevilla 

 
 
• 

• 

• 

Cadiz 

Malaga 

Murcia 

These information is reported in more detail in: 

https://www.autopista.es/noticias-motor/todas-las-ciudades-de-espana-y-europa-con-limite-
de- velocidad-a-30-km-h_156186_102.html) 

http://en.30kmh.eu/files/2015/11/30-kmh-TRENDSETTER-CITIES.pdf 

1.3.9. Review  of  information  regarding  PTI  (periodical  technical 

inspections in Europe. 

The  reason  to  get  information  on  how  PTI  is  applied  to  L-category  vehicles  is  to  know  the 
degree of in-use controls applied to these vehicles in the EU countries. PTI is not related to 
type approval, but it has a direct impact on the control of non-conforming vehicles found on EU 
roads. 

After contacting CITA we got as a main source of information the “Study on the inclusion of 
light  trailers  and  two-  or  three-wheel  vehicles  in  the  scope  of  the  periodic  roadworthiness 
testing” published in February 2019. 

The more relevant information found for the purpose of the EURO 5 sound limits study on L-
category vehicles is: 

•  The list of EU countries where PTI is mandatory for motorcycles (to be understood in most 
cases as L-category vehicles). Table 9 displays which Member States have compulsory 
PTI  for  motorcycles  in  place.  Note  that  Belgium,  Cyprus,  Denmark,  Finland,  France, 
Ireland, Malta, the Netherlands and Portugal do not have that requirement: 

Table 9: PTI in EU Member States and the UK. 

96 

 
 
 
•  One  source  of  data  regarding  the  types  of  deficiencies  and major  deficiencies  detected 

during PTIs comes from Spain (2016). 

Figure 42 

Among the topics identifying the deficiencies in Spain there isn’t a specific measurement of the 
noise-related issues. 

Then,  it  is  not  possible  to  identify  the  degree  of  failures  regarding  the  performance  of  the 
exhaust system on sound level emissions. 

•  Another information source comes from Germany (2017) 

In this case one of the identified failure sources is nuisance, but it is impossible to discriminate 
if this nuisance comes from emission of gaseous pollutants or from high sound level emissions. 

In  any  case,  if  for  Spain  and  Germany  data  we  take  “polluting  emissions”  or  “nuisance” 
respectively as a criterion including both pollutants and sound emissions this topic accounted 
for 10%-13% of the total detected PTI deficiencies on motorcycles. 

 
 
 
 
 
Figure 43 

•  Other information 

Additionally, in this study there is data regarding the 2015 motorcycle fleet in EU:  

98 

 
 
 
 
 
 
Table 10: Number of motorcycles in EU Member States (2015) 

1.3.10. Urban and extra-urban noise levels 

In this section we aim to understand the statistical distribution of the number of people affected 
by various levels of urban, rail, aircraft and industrial noise for urban and extra-urban scenarios. 
The  information  below  shows    the  relative  contribution  of  the  various  noise  sources  to  the 
global annoyance, and thus it is fundamental to identify the most effective actions to reduce 
the global noise effects. 

Table  11  shows  the  latest  estimations  of  population  exposure  for  the  most  recent  round  of 
noise mapping within and outside urban areas for the 33 EEA member countries (EEA-33), 
excluding Turkey. The overall number of people exposed to day- evening-night noise levels of 
55 dB or higher is estimated to be 113 million for road traffic noise, 22 million for railway noise, 
4 million for aircraft noise and less than 1 million for noise caused by industries. Similarly, road 
traffic is by far the biggest source of environmental noise during the night- time, followed by 
railway, air and industrial noise. 

Considering road traffic noise only, these results indicate that at least 20% of Europeans are 
exposed to high levels of noise during the day-evening-night period and more than 15% during 
the night-time period, from which adverse health effects can occur. 

 
 
 
 
Table 11: Population exposure to environmental noise, based on areas covered by 
strategic noise maps in 2017, EEA-33 (Turkey not included) 

Number of people exposed to 

Number of people  exposed to 

Lden ≥ 55dB (Million) 

Lnight ≥ 55dB (Million) 

Reported 

Estimated 

Reported 

Estimated 

Inside urban areas (road) 

Outside urban areas (road) 

50.6 

21.8 

81.7 

31.1 

33.8 

14.2 

57.5 

21.1 

The coverage under the Environmental Noise Directive (END) is: 

 

Inside  urban  area:  Roads,  railways,  airports  and  industries  inside  urbanized  areas 
(called  agglomerations)  with  a  population  exceeding  1.000.000  inhabitants  and  a 
population density such that the Member State considerer it to be an urbanized area. 

  Outside  urban  area:  This  includes  Major  roads  (>  3.000.000  passages/year),  major 
railways (> 30.000 passages/year) and major airport (> 50.000 movements/year) 

Figure 42 shows the exposure data, as reported by EEA member countries, for noise bands 
above  55  dB  Lden.  Most  of  the  people  are  exposed  to  the  lowest  decibel  band  (55-60  dB). 
However, there is still a considerable number affected by higher levels of noise, in particular 
road traffic noise both inside and outside urban areas. Specifically, there are approximately 12 
million people exposed to very high noise levels of road traffic noise equal to or higher than 70 
dB Lden. 

This figure shows the relative importance of road noise as an annoyance source compared 
with rail, air and industrial contributions. 

Figure 44: Number of people exposed to various Lden noise bands based on the areas covered by the strategic noise maps in 
2017, EEA-33 (Turkey not included). 

Figure 43 shows the distribution of the exposed population within each source, per noise band, 
using Lden indicator in 2017, EEA-33. We note that road traffic noise is the noise source with 

100 

 
 
 
  
 
 
 
the  highest  percentage  of  people  exposed  to  the  upper  bands,  starting  from  70  dB  Lden. 
However, of the people exposed to aircraft noise both inside and outside urban areas, only a 
small proportion are exposed to the highest noise categories. This is true for both urban and 
extra-urban environments. 

Figure 45: Distribution of the exposed population within each source, per noise band, using Lden indicator in 2017, EEA-33. 

Figure 44 shows that night-time noise affects fewer people in the higher noise bands. As for 
the day-evening-night period, road traffic noise is the noise source that has the highest number 
of people exposed to very high levels of noise (≥ 65 dB) during the night-time. 

Figure 46: Number of people exposed to various Lnight noise bands based on the areas covered by the strategic noise maps in 
2017, EEA-33 (Turkey not included) 

However,  as shown in  Figure  45,  railway  noise is  the  source  with  the  highest  proportion  of 
people exposed to levels falling in the upper bands of the spectrum (≥ 65 dB) during the night-
time. 

 
 
 
 
Figure 47: Distribution of the exposed population within each source, per noise band, using Lnight indicator in 2017, EEA-33. 

1.3.11. Health impact of exposure to environmental noise 

Prolonged exposure to environmental noise is one of the major environment related causes of 
ill health in Europe. Traffic noise, including road, rail and air traffic, has been classified as the 
second environmental threat to public health in western Europe, behind fine particulate matter 
(WHO  and  JRC,  2011;  Hänninen  et  al.,  2014).  Although  the  levels  of  noise  generated  by 
transport  sources  are  generally  too  low  to  cause  biological  damage  to  the  ear,  it  is  well 
established that, if exposure is long term and exceeds certain levels, noise can lead to non-
auditory  health  effects  such  as  annoyance,  sleep  disturbance,  negative  effects  on  the 
cardiovascular and metabolic system as well as cognitive impairment in children (WHO, 2018). 

The most severe effects of noise on health, such as those on the heart and circulatory system 
that  can  lead  to  premature  mortality,  are  hypothesised  to  be  triggered  by  long-  term 
physiological and emotional stress reactions as well as a reduction in sleep quality (Eriksson 
and  Pershagen,  2018;  Basner  et  al.,  2014).  These  reactions  may  also  affect  the  metabolic 
system. 

Description of the main non-auditory adverse health effects of noise 

The main recognised non-auditory adverse health effects of noise are as follows 

Annoyance 

It is one of the most prevalent responses to noise, and it is described as a stress reaction that 
encompasses  a  wide  range  of  negative  feelings,  including  disturbance,  dissatisfaction, 
distress,  displeasure,  irritation  and  nuisance. The  individual  response to  noise depends  not 
only on exposure levels but also on contextual, situational and personal factors. It can initiate 
physiological  stress  reactions 
the  development  of 
cardiovascular disease. 

long-term,  could 

trigger 

that, 

if 

Sleep disturbance 

Sleep  serves  to  facilitate  vital  functions  in  our  body.  Noise  fragments  sleep,  reduces  sleep 
continuity and reduces the total amount of sleep time, which can have impacts on alertness, 
performance at work and quality of life. Sleep restriction causes, among other things, changes 
in  glucose  metabolism  and  appetite  regulation,  impaired  memory  consolidation  and  a 
dysfunction  in  blood  vessels.  Long-term  sleep  disturbance  can  also  lead  to  cardiovascular 
health issues. 

102 

 
 
 
 
Cardiovascular and metabolic effects 

Noise  is  an  important  risk  factor  for  chronic  diseases.  Noise  exposure  activates  stress 
reactions  in  the  body,  leading  to  increases  in  blood  pressure,  a  changing  heart  rate  and  a 
release of  stress  hormones. In  addition,  the  cardiovascular  and metabolic  effects related  to 
noise exposure may also be a consequence of a reduction in sleep quality, caused by noise 
exposure during the night, among other additional or interrelated mechanisms. These chronic 
effects can lead to premature mortality. 

According to the WHO environmental noise guidelines, the noise indicator that define the limits 
strongly  recommended  for  traffic  noise  (road)  are  the  Lden  and  Lnight.  These  parameters  are 
defined next: 

Lden is the day-evening-night level. It is a descriptor of noise level based on energy equivalent 
noise level (Leq) over a whole day with a penalty of 10 dB(A) for night time noise (23.00-7.00) 
and an additional penalty of 5 dB(A) for evening noise (i.e. 19.00- 23.00). It is defined as, 

𝐿𝑑𝑒𝑛 = 10 ∗ log

1
24

where, 

(12 ∗ 10(0.1∗𝐿𝑑𝑎𝑦) + 4 ∗ 10(0.1∗(𝐿𝑒𝑣𝑒𝑛𝑖𝑛𝑔+5)) + 8 ∗ 10(0.1∗(𝐿𝑛𝑖𝑔ℎ𝑡+10)), 

(1) 

Lday is the A-weighted long-term average sound level as defined in ISO 1996- 2:1987, 

• 
determined over all the day periods of a year. 

Levening  is  the  A-weighted  long-term  average  sound  level  as  defined  in  ISO  1996-  2: 

• 
1987, determined over all the evening periods of a year. 

Lnight is the A-weighted long-term average sound level as defined in ISO 1996-2: 1987, 

• 
determined over all the night periods of a year, 

in which, 

• 
The day is twelve hours, the evening four hours and the night eight hours. The Member 
States may shorten the evening period by one or two hours and lengthen the day and/or night 
period  accordingly,  provided  that  this  choice  is  the  same  for  all  the  sources  and  that  they 
provide the Commission with information on any systematic difference from the default option. 

The start of the day (and consequently the start of the evening and the start of the night) 
• 
shall be chosen by the Member State (that choice shall be the same for noise for all sources); 
the default values are 07.00 to 19.00, 19.00 to 23.00 and 23.00 to 07.00 local time. 

A year is a relevant year as regards the emission of sound and an average year as 

• 
regards the meteorological circumstances. 

The recommended limits for Lden and Lnight in Europe for traffic noise are (WHO 2018): 

Lden: 53 dB 

Lnight: 45 dB 

• 

• 

𝐿𝑅𝑑e𝑛

It is worth noting that the general expression for the composite whole-day rating level that, 

𝐿𝑅𝑑𝑒𝑛 = 10 ∗ log(

𝑑
24

∗ 10(0.1∗(𝐿𝑅𝑑+ 𝐾𝑑)) +

𝑒
24

∗ 10(0.1∗(𝐿𝑅𝑒+ 𝐾𝑒)) +

24−𝑑−𝑒
24

∗ 10(0.1∗(𝐿𝑅𝑛+ 𝐾𝑛)), 

(2) 

where: 

• 

• 

• 

d, e and n is the number of day, evening and night ours per day, respectively. 

LRd is the rating level for day time 

LRn is the rating level for night time 

 
 
 
• 

• 

LRe is the rating level for evening time 

Kd, Kn and Ke are the adjustments for day, night and evening times respectively. 

The values of Kd, Kn and Ke are defined in ISO 1996-1 (Annex 1) as adjustments for sound 
source rating levels. The adjustments for ‘time period’ corresponding to the day, evening and 
night periods are 0, 5 and 10 hours respectively. 

On the other hand, the terms LRd, LRn and LRe are the equivalent continuous sound pressure 
level which is ten times the logarithm to the base 10 of the ratio of the square of the mean-
square  sound  pressure  over  a  stated  time  interval  to  the  square  of  the  reference  sound 
pressure. That is, 

𝐿𝑅𝑑 = log[

1
𝑇𝑑

𝐿𝑅𝑛 = log[

1
𝑇𝑛

2 𝑡𝑑
2) 𝑑𝑡]
𝑝𝑜

 , 

∫ (𝑝Æ
𝑡𝑑

2 𝑡𝑛
2) 𝑑𝑡]
𝑝𝑜

 , 

∫ (𝑝Æ
𝑡𝑛

𝐿𝑅𝑒 = log[

1
𝑇𝑒

2 𝑡𝑒
2) 𝑑𝑡]
𝑝𝑜

∫ (𝑝Æ
𝑡𝑒

 . 

(3) 

(4) 

(5) 

If we call LRd, LRn and LRe as Lday, Lnight and Levening respectively and take Td , Tn and Te equal to 
12 hours,4 hours and 8 hours respectively, then equation (2) becomes equation (1), which is 
defined  in  Directive  2002/49/EC  and  coincides  with  the  definition  of  the  Day-Evening-Night 
level (Lden) in decibels. 

The estimated percentage of people in the category of Highly Annoyed (HA) by traffic noise 
according to the WHO environmental noise guidelines is given in Figure 46. We note that the 
percentage of Highly Annoyed people for Lden = 53 dB is about 10%. 

Figure 48: The relationship between the percentage of Highly Annoyed people (HA) versus Lden. According to Miedema (2001) 
and WHO (2018). 

Figure 47 depicts the estimated percentage of people in the category High Sleep Disturbed 
(HSD)  by  traffic  noise  from  the  WHO  environmental  guidelines.  We  observe  that  the 
percentage of HSD people for Lnight = 45 dB is about 5%. 

104 

 
 
Figure 49: The relationship between the percentage of Highly Sleep Disturbed people vs. Lnight 

according to WHO (2009) and WHO (2018). 

These recommendations define an exposure level above which a relevant increase in negative 
effects occur, expressed in terms of Lden and Lnight, which relate to outdoor noise as an annual 
average. The recommendations for all sources of traffic noise were considered to be 'strong', 
meaning  that  the  recommendation  can  be  adopted  as  policy  in  most  situations.  These 
guideline  values  are  based  on  the  confidence  that  reducing  noise  to  the  stated  levels  will 
outweigh  the  potential  adverse  consequences.  However,  the  guidelines  do  not  include 
recommendations  for  locations  exposed  to  noise  from  a  combination  of  sources  or  for 
vulnerable groups. 

Health impact and burden of disease 

The impact of noise pollution in Europe are highly significant. It is estimated that around 22 
million adults living in agglomerations or near major noise sources with levels starting at 55 dB 
Lden are highly annoyed by noise from road traffic, railways, aircraft and industry. Moreover, it 
is estimated that 6.5 million adults suffer severe sleep disturbance because of night-time noise 
levels equal to or above 50 dB Lnight. The exposure to environmental noise from road traffic, 
railways, aircraft and industry is estimated to contribute every year to about 48000 new cases 
of ischaemic heart disease and 12 000 premature deaths. In particular, a brake down of the 
health impact of road noise on urban and extra-urban areas is shown in Table 12. 

Table 12: Estimated number of people suffering from various health problems due to road 
noise in 2017. EEA-33 (Turkey not included) 

High 
annoyance 

High sleep 
disturbance 

Ischaemic heart 
disease 

Premature 
mortatility 

Inside urban 
areas 

Outside urban 
areas 

Total 

12500000 

3240000 

29500 

7600 

4620000 
17120000 

1200000 
4440000 

10900 
40400 

2500 
10100 

Figure 48 depicts the values of Table 12 and compares them for urban an extra-urban areas. 

 
 
 
 
 
 
 
 
 
 
 
 
Figure 50: Curves showing the data in Table 12 

Table 13 shows the burden of disease results estimated from the noise data covered by the 
END. This burden can be estimated in terms of the parameter called DALY. One DALY can be 
thought of as one lost year of "healthy" life. The sum of these DALYs across the population, or 
the burden of disease, can be thought of as a measurement of the gap between current health 
status and an ideal health situation where the entire population lives to an advanced age, free 
of disease and disability. 

DALYs for a disease or health condition are calculated as the sum of the Years of Life Lost 
(YLL) due to premature mortality in the population and the Years Lost due to Disability (YLD) 
for people living with the health condition or its consequences. 

DALYs lost due to noise-induced health outcomes were estimated to be equivalent to 437 000 
years for sleep disturbance, 453 000 years for annoyance, 156 000 years for heart disease 
and 75 years for cognitive impairment of children. Although a simple summation of DALYs for 
each health effect may lead to some double counting, the results tentatively indicate that about 
1  million  healthy  years  of  life  are  lost  every  year  as  a result  of  environmental  noise for  the 
health effects assessed. In terms of individual noise sources, road traffic noise — as the most 
prevalent source of environmental noise— not surprisingly has the largest contribution to the 
burden of disease due to noise (75 %). 

Figure 49 shows the percentage of public health impact in DALY’s year for the various health 
effects considered. It represents the burden of disease due to the environmental noise sources 
covered by END, EEA-33, with Turkey not included. 

Table 13: Burden of disease due to the environmental noise covered by END (Turkey not 
included) 

106 

 
 
 
Figure 51: The percentage of public health impact in DALY’s year for the various health effects considered. 

The economic impact associated to the decline in the population's health because of noise has 
an economic impact in Europe. There are different approaches for quantifying the economic 
costs of noise on health, one of which relies on assigning a monetary cost per DALY (Defra, 
2014).  Although the  assessment  of the  costs  in terms  of  DALYs  may  differ from  country  to 
country,  if  we  assume  that  the  monetary  cost  per  DALY  is  EUR  78500  (VITO,  2003),  the 
resulting economic impact of noise is estimated to be EUR 35 billion for annoyance, EUR 34 
billion  for  sleep  disturbance,  EUR  12  billion  for  ischaemic  heart  disease  (IHD)  and  EUR  5 
million for cognitive impairment in children. Monetary costs can also exist as a result of reduced 
house prices, loss of labour days and reduced possibilities for land use. 

1.3.12. Considerations  about  the  annoyance  from  scooters  and 

motorbikes noise 

Regarding  urban  road  transportation  noise,  it  is  rather  common  to  hear  from  people  that 
Powered Two Wheelers (PTW) are annoying, and many times are actually the most annoying 
environmental noise sources. 

This  perception  is  associated  with  the  fact  that  the  noise  of  the  PTW  produces  additional 
annoyance  for  the  population  living  in  urban  areas  and,  in  particular,  in those  areas  where 
people are directly exposed to noise as in the case of pedestrians, people living at home but 
using terraces  or  living  indoors  with open  windows,  and people in outdoor  bars  and  shops. 
Surprisingly, the PTW are also a source of annoyance in countries where they are not largely 
used. Studies in The Netherlands (Franssen et al., 2004) and UK (Sound Public Support for 
Quiet Areas, 2009) showed that scooters are amongst the most annoying noise sources in the 
country. 

The outdoor annoyance from scoter and motorbike noise in a real urban environment has been 
investigated  by  Paviotti  and  Vogiatzis  (2012).  In  their  research,  carried  out  in  Athens  city 
centre, both scooters and motorbikes operation patterns were analysed, on the basis of their 
environmental impact through ad-hoc tests to establish if specific features of their emitted noise 
are annoying. Their investigation was based on the characterisation of the averaged individual 
pass-by noise produced by the vehicles of the circulating fleet. Among other considerations, 
they showed that a parameter which is considered to be well correlated with noise annoyance 
is the LAmax. The following considerations must be taken into account: 

  The assumption is justified by the fact that, within a standard urban traffic noise, short 
time  but  high  LAeq  noise  levels  (above  the  average  background  noise)  could  be 
identified as those attracting people’s attention (De Coensel et al., 2009) and 

 Public health impact DALY's/year 15% 43% High annoyance  High sleep disturbance 42% Ischaemic heart disease (IHD)  
 
 
 

If these acoustic events can be attributed mainly to PTW, it is likely that the PTW would 
be regarded as annoying by individuals. 

They found that for a half of the PTW pass-by measurements, the results showed that their 
LAmax was much higher than the LAmax of any car pass-by. Looking at the energetic averages of 
the  LAmax  of  the  three  vehicles  categories  considered  (cars,  scooters  and  motorbikes),  for 
scooters  they  were  4.5  dB  higher  than  cars,  and  for  motorbikes  8.7  dB  higher.  As  a 
consequence of such a wide discrepancy amongst levels (see Figure 52, the assumption that 
in  standard  road  traffic,  noise  from  PTW  pass-by  is  generally  noticeable  and  may  distract 
people or even strongly attract attention seems acceptable. 

However, a condition for PTW noise to be perceived as annoying is that the frequency of PTW 
pass-by should be small. In fact, if PTW are frequently present in the traffic, distraction does 
not  occur  anymore  since  the  high  noise  levels  tend  to  become  constant  in  time,  and  it  is 
believed, as explained in the past literature (De Coensel et al., 2009), that annoyance caused 
by distraction will not occur. 

Indeed, by looking at both LAmax and loudness recorded, a good correlation that follows this 
rule emerged: scooters emit 4.5 dB more than cars corresponding to 5.9% louder; motorbikes 
emit 6.7 dB higher corresponding to 8.9% louder (See Table 14) . It seems therefore that LAmax 
and loudness can be alternatively used to classify a major distinguishing feature of the PTW 
against the cars in terms of annoyance 

Table 14: Average acoustic parameters recorded in the measurements recorded in Athens 
city centre (after Paviotti and Vogiatzis – 2012). 

In the research, a detailed analysis was conducted based on past and new elements towards 
establishing if PTW are annoying within specific traffic conditions and what are the annoying 
features. Based on the literature review and on the new evidence it is clear that annoyance is 
reported by people actually hearing the PTW within the traffic, and that PTW are amongst the 
most  annoying  sound  sources,  and  therefore  there  is  an  increasing  need  for  attention 
(Racioppi et al., 1999). Though, due to the uncertainty of the above, conflicting evidence seems 
to exist as to the reason why the PTW are indeed annoying. There are two features that allow 
the classification of the PTW: the maximum noise levels and the roughness. Because it has 
been shown that LAeq cannot be used alone to qualify annoyance. 

To explain the results found by Paviotti and Vogiatzis it is necessary to consider the effect of 
masking  and  the  distraction  induced  in  the  individuals  (De  Coensel  et  al.,  2009):  when  the 
noise  of  the  PTW  is  “masked”  by  an  increased  general  traffic,  including  the  cars,  then  the 
individuals hearing the noise of the PTW mix it with that of the traffic. For example, in one of 
the sites in the tests in Athens it was reported that the percentage of annoyed individuals by 
PTW was about 16% lower than those annoyed by the PTW and cars all together, although 
the PTW noise is the most relevant in terms of LAeq. 

On the other hand, when PTW are heard in a sufficiently quiet environment, so as to be able 
to  univocally  associate  the  specific  noise  signature  of  the  PTW  to  the  PTW  itself,  it  seems 
highly probable that distraction occurs and the combined high maximum noise level and the 
roughness of the sound “impress” the listener at a negative level. These two combined features 
put the PTW noise amongst the more annoying ones. 

108 

 
 
 
Figure 52: Distributive and cumulative curves of the percentage of LAmax measured for the pass-by recorded in Athens city 
centre. The cars show lower noise levels than scooters and motorbikes. 

 
 
 
Figure 53: Distributive and cumulative curves of the percentage of loudness (maximum during 5% of time) measured for the 
pass-by recorded in Athens city centre. The cars show lower loudness than scooters and motorbikes. 

1.3.13. Environmental impact of road noise on biodiversity 

Although the main objective of the Environmental Noise Directive (END) is solely to reduce the 
harmful effects of noise on human health, noise from a variety of transport and industry sources 
also affects wildlife. Whether in the terrestrial or the marine environment, many species rely 
on  acoustic  communication  for  important  aspects  of  life,  such  as  finding  food  or  locating  a 
mate.  Anthropogenic  noise  sources  can  potentially  interfere  with  these  functions  and  thus 
adversely affect diversity of species, population size and population distribution. 

The effects of noise on animals may manifest in both physiological responses and behavioural 
responses  (Figure  52).  Some  studies  have  observed  that  noise  may  cause  stress,  hearing 
damage and a reduced immune system in animals. For instance, a study conducted in France 
showed that traffic noise produces stress responses in frogs that may alter their metabolism 
and immune  system  as well  as  their  vocal  sac  colouration (Troïanowski et  al.,  2017).  Birds 
have also shown signs of chronic stress, such as skewed stress hormone levels, distraction 
and hypervigilance, when exposed to noise pollution (Kleist et al., 2018). 

110 

 
 
 
Figure 54: Mechanisms involved in the impact of anthropogenic noise. 

There  is  a  wide  range  of  impacts  that  involve  behavioural  responses  in  animals.  It  is  well 
documented  that  noise  may  cause  changes  in  activities  and  sleep  patterns,  alterations  in 
space use and movements, changes in the efficiency of foraging and provisioning of young, 
changes  in  vocal  communication  and  mating  behaviour  as  well  as  changes  in  territorial 
defence, vigilance and anti-predator behaviour. 

These  physiological  and  behavioural  responses  can  lead  to  reduced  reproductive  success, 
increased mortality risk and emigration, resulting in reduced population densities (Francis and 
Barber,  2013).  However,  the  effects  of  traffic  noise  on  animals  vary  markedly  among 
individuals as well as within species, owing to a variety of factors, including age, sex, sensitivity 
and prior exposure. Likewise, the impacts also depend on noise characteristics, such as noise 
intensity,  duration,  noise  frequency  and  the  type  of  noise.  Therefore,  as  a  result  of  these 
differences between species and between noise characteristics, it has been difficult to set a 
noise level that avoids ecological consequences, although, at least for terrestrial environments, 
effects  have  been  documented  for  low  levels  of  environmental  and  transport  noise  starting 
between 40 and 50 dB(A) (Shannon et al., 2016). 

There is currently no specific EU noise legislation aimed at protecting terrestrial wildlife from 
noise  exposure.  The  obligations  under  the  END  mainly  focus  on  reducing  the  impact  of 
environmental noise on human health and well-being by reducing noise from roads, railways, 
airports and industries to levels below 55 dB Lden and 50 dB Lnight. However, these are human-
based impact indicators and may not be entirely comparable with the ones used to assess the 
impacts of noise on animals (e.g. Leq, Lmax). Nevertheless, effects generated at levels below 
the END thresholds may be possible, given that some studies recorded effects between  40 
and  50  dB  LAeq.  The  END  recognises  the  need  to  preserve  areas  of  good  acoustic quality, 
referred to as 'quiet areas', to protect the European soundscape, but it does not make a link 
with wildlife 

In  2014,  the  EEA  developed  a  methodology  to  measure  potential  quiet  areas  in  the  open 
country  called  the  Quiet  Suitability  Index  (QSI).  This  index  is  based  on  the  combination  of 
contour maps that exceed the Environmental Noise Directive thresholds of 55 dB Lden and land 
use and land cover elements that indicate naturalness using the hemeroby index. This index 
ranges from 0 (noisy areas) to 1 (quiet areas). Using this methodology, the EEA derived a map 
at European level showing potential quiet areas, to obtain complete European coverage when 
contour maps were not available. 

Figure  53  shows  the  potential  quiet  and  non-quiet  areas  in  the  33  EEA  member  countries 
(EEA-33).  The  protected  sites  in  relation  to  Natura  2000  are  shown  together  with  the 

 
 
 
percentage of country areas in each range of the Quietness Suitability Index (QSI). The land 
area considered potentially noisy makes up approximately 1594451 km2 across the EEA-33 
(excluding  Croatia  and  Turkey).  In  other  words,  noisy  or  relatively  noisy  areas  (QSI  <  0.5) 
account for 33 % of the EEA-33 territory. In addition to this, it is estimated that about 19% of 
the Natura 2000 sites are located in areas considered noisy. It is therefore worth considering 
the preservation of natural acoustic conditions to limit biodiversity loss. 

Figure 55: Potential quiet areas in Europe, based on the Quietness Suitability Index (QSI) and Natura 2000 protected sites. 

112 

 
 
 
 
2. Verification of sound level limits 

2.1. Vehicle testing – sound level measurements 

The objective of including vehicle testing with sound measurements in the Task 2 of the study 
is to establish representative current sound levels within the L-category vehicles fleet in order 
to have a direct evaluation of the current sound emissions and have a perception of the margin 
for improvement of sound level performance. 

2.1.1. Vehicle’s selection justification 

The vehicles have been selected according to various criteria within the current homologated 
vehicles for each L-category defined in the scope of the study. 

The main criteria were the following: 

•  Cover all the L-category vehicles categories defined in this study 

•  According to Task 1 of this study, test the vehicles perceived as more relevant in terms of 

noise impact on the European public roads 

• 

Include a wide range of powertrain configurations 

•  Represent the current fleet of vehicles in Europe 

•  Recent EU WVTA certificates 

Table 15 summarizes the vehicles selected for testing according to UN Regulation 41.04 and 
UN Regulation 09.08 (18 vehicles in total) and its specifications: 

Table 15 

UN-Regulation 

PMR 

Category / 
Sub-category 

Engine 
type 

Gear / 
Transmission 

25 < PMR ≤ 50 

R.41.04 

PMR > 50 

R.09.08 

PMR ≤ 50 
PMR > 50 
PMR ≤ 50 
PMR > 50 
(With ASEP) 

L3e-A1 
L3e-A1 
L3e-A1 
L3e-A2T 
L3e-A3 

L3e-A3 

L3e-A3 

L3e-A3 

L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 
L5e-B 
L5e-A 
L6e-BP 

L7e-B1 

PI 
PI 
PI 
PI 
PI 

PI 

PI 

PI 

PI 
PI 
PI 
PI 
PI 
PI 
PI 
PI 
PI 

PI 

Locked / Manual 
Non-locked / CVT 
Locked / Manual 
Locked / Manual 
Locked / Manual 

Type of vehicle 

Enduro 
Urban Scooter 
Sport 
TRIAL 
Sport Naked 

Locked / Manual 

Sport TRAIL 

Locked / Manual 
Non-locked / 
Automatic 
Locked / Manual 
Locked / Manual 
Locked / Manual 
Non-locked / CVT 
Locked / Manual 
Locked / Manual 
Locked / Manual 
Non-locked / CVT 
Non-locked / CVT 

Sport 

Sport TRAIL 

Sport TRAIL 
Sport TRAIL 
Sport Naked 
Urban Scooter 
Touring 
Custom 
Bodied Tricycle 
Unbodied 
Bodied 

Non-locked / CVT 

ATV 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2.1.2. Category definition 

The classification criteria according to Annex I to Regulation EU No.168/2013 as last amended 
by Regulation EU No. 2020/1694 of the vehicles included in this study are: 

114 

 
 
 
 
 
 
2.1.3. Acronyms and symbols 

Symbol 

AA’ 
awot 
awot,ref 
aurban 
BB’ 
CC’ 
K 
kp 
L 
L wot(i) 
LASEP 
lPA 
mkerb 
mt 
N 
nPP’ 
nidle 
nwot(i) 
PP’ 
PMR 
Pn 
S 
V 
Vmax 
Vtest 
Wot 
CRS 

Units 
- 
m/s2 
m/s2 
m/s2 
- 
- 
- 
- 
dB(A) 
dB(A) 
dB(A) 
M 
kg 
kg 
min-1 
min-1 
min-1 
min-1 
- 
- 
kW 
min-1 
km/h 
km/h 
km/h 
- 
- 

Explanation 

Virtual line on the test track 
Calculated acceleration 
Prescribed reference acceleration 
Prescribed target acceleration 
Virtual line on the test track 
Virtual line on the test track 
Gear weighting factor 
Partial power factor 
Sound pressure level 
L at wot condition 
L at RD-ASEP additional operating conditions 
Pre-acceleration length 
Kerb mass of the vehicle 
Test mass of the vehicle 
Engine speed 
Engine speed at PP’ 
Engine speed at idle 
npp’ measured at Lwot(i) detection 
Virtual line on the test track 
Power-to-mass ratio index 
Rated maximum net power 
Rated engine speed 
Measured vehicle speed 
Maximum speed 
Rated engine speed 
Denoting a full throttle acceleration test 
Denoting a constant speed test 

 
 
 
 
Urban 

- 

WVTA 
2.2. Testing procedures 

- 

Denoting a weighted combination of a constant speed test and a 
full throttle acceleration test 
Whole vehicle type approval 

Sound level tests have been carried out on test tracks certified according to ISO 10844:2014 
and following the testing procedures relative to each vehicle category: 

L3e (two-wheel motorcycles): UN Regulation 41.04. 

L5e (tricycles), L6e, L7e (quadricycles): UN Regulation 09.08. 

In addition, four L3e motorcycles have been tested according to the proposal of the new 05 
series amendments to UN Regulation No. 41. 

The inclusion of RD-ASEP conditions is the main difference of this new proposal against the 
current UN Regulation No.41 prescriptions. 

UN Regulation 41.04 operating conditions 

Motorcycles with a power to mass ratio (PMR) up to 25 W/kg 

The vehicle is tested in a full throttle acceleration test with the following specifications: 

a) 

The test speed (vtest) shall be = 40 ± 1 km/h. 

b) 
When the rear of the vehicle passes the line BB' the vehicle speed shall not exceed 
75% of the maximum vehicle speed neither shall the engine speed exceed the rated engine 
speed. 

vtest is related to the line PP’ (see Figure 1). 

The gear for the test shall be selected in the following iterative way: 

The  initial  test  speed  shall  be  as  specified  above.  The  test  speed  shall  be  reduced  by 
increments of 10 percent of vtest (i.e. 4 km/h) in case the exit speed vBB' exceeds 75 percent 
of vmax or in case the engine speed exceeds the rated engine speed at BB'. The selected 
gear shall be the lowest one without exceeding the rated engine speed during the test. The 
final test conditions are determined by the lowest possible gear at the highest possible test 
speed without exceeding either 75% of vmax or the rated engine speed at BB'. 

Motorcycles with a power to mass ratio (PMR) > 25 W/kg 

The vehicle is tested in a full throttle acceleration test and in a constant speed test. 

For the full throttle acceleration tests the test speed and the mean acceleration of the vehicle 
in the test track are specified. 

The test speed (vtest) at line PP’ (see Figure 16 below) shall be: 40 ± 1 km/h for vehicles with 
a PMR ≤ 50; and 

50 ± 1 km/h for vehicles with a PMR > 50. 

If, in a given gear, the exit speed vBB' exceeds 75% of the maximum speed vmax of the vehicle, 
the test speed for test in this gear shall be successively reduced by increments of 10 percent 
of vtest (i.e. 4 km/h or 5 km/h) until the exit speed vBB' falls below 75% of vmax. 

During the full throttle acceleration tests the vehicle shall reach the reference acceleration awot 
ref defined as: 

awot ref = 2,47 * log(PMR) – 2,52 for vehicles with a PMR ≤ 50; and awot ref = 3,33 * log(PMR) 
– 4,16 for vehicles with a PMR > 50. 

116 

 
The results of these full throttle acceleration tests are used together with the results of constant 
speed  tests  to  approximate  a  partial  load  acceleration  typical  for  urban  driving.  The 
corresponding target acceleration aurban is defined as: 

aurban = 1,37 * log(PMR) – 1,08 for vehicles with a PMR ≤ 50; and  

aurban = 1,28 * log(PMR) – 1,19 for vehicles with a PMR > 50. 

For  vehicles  with  manual  transmissions,  automatic  transmissions,  or  transmissions  with 
continuously variable transmission ratios (CVT) tested with locked gears, the selection of gears 
for  the  test  depends  on  the  specific  acceleration  under  full  throttle  in  the  various  gears  in 
relation to the reference acceleration awot,ref required for the full-throttle acceleration tests. 

The following conditions for the gear selection are possible: 

a) 
If there are two gears that give an acceleration in a tolerance band of ±10 percent of 
the reference acceleration awot,ref, the gear nearest the reference acceleration shall be used 
for the test and shall be identified as such in the test report. 

If only one specific gear gives an acceleration in the tolerance band of ±10 percent of 

b) 
the reference acceleration awot ref, the test shall be performed with that gear. 

If  none  of  the  gears  gives  the  required  acceleration  to  within  ±10  percent  of  the 

c) 
reference acceleration awot,ref, then tests shall be performed in two adjacent gears 

and (i + 1) chosen such that the gear (i), gives an acceleration higher and the gear (i + 

(i) 
1) an acceleration lower than the reference acceleration awot,ref. 

If the rated engine speed is exceeded in a gear before the vehicle passes BB', the next higher 
gear shall be used. If the vehicle has more than one gear the first gear shall not be used. If 
awot,ref can only be achieved in first gear, second gear shall be used. 

For  vehicles  with  automatic  transmissions,  adaptive  transmissions  or  transmissions  with 
variable  transmission  ratios  tested  with  non-locked  gears  the  gear  selector  position  for  full 
automatic operation shall be used. 

For the constant speed tests the gears or gear selector positions and the test speeds shall be 
identical to those used in the full throttle acceleration tests previously performed. 

If two gears are to be tested, the gear weighting factor "k" is used to combine the results from 
both gears into a single result. The gear weighting factor is a dimensionless number defined 
as: 

k = (awot,ref - awot,(i + 1)) / (awot(i) - awot,(i + 1)) 

If the vehicle was tested in two gears the gear weighting factor k is used to calculate the test 
results of the full throttle acceleration tests and of the constant speed tests: 

Lwot = k * (Lwot,(i) + (1 - k) * Lwot,(i + 1)) 

Lcrs = k * (Lcrs,(i) + (1 - k) * Lcrs,(i + 1)) 

If  the  vehicle  was  tested  in  a  single  gear  or  gear  selector  position  no  further  weighting  is 
necessary: 

Lwot = Lwot,(i) Lcrs = Lcrs,(i) 

The sound pressure level Lurban representing the final result is calculated using the partial power 
factor kp: 

Lurban = kp * Lcrs + (1 - kp) * Lwot 

For vehicles tested in two gears the partial power factor is defined as  

kp = 1 - (aurban / awot,ref). 

 
 
For vehicles tested in a single gear or with the gear selector in one position the partial power 
factor is defined as: 

kp = 1 - (aurban / awot,(i)) 

If awot,(i) is equal to or less than aurban, kp is set to zero. 

Figure 56: Testing track and measuring positions. 

Sound level limits 

Current sound level limits for L3e motorcycles are: 

Category 
First category 
Second category 
Third category 

Table 16: Lurban limits. 

Power-to-mass ratio index (PMR)  Limit value for Lurban in dB(A) 

PMR ≤ 25 
25 < PMR ≤ 50 
PMR > 50 

Table 17: Lwot limits. 

73 
74 
77 

Category 
First category 
Second category 
Third category 

Power-to-mass ratio index (PMR) 
PMR ≤ 25 
25 < PMR ≤ 50 
PMR > 50 

Limit value for Lwot in dB(A) 
78 
79 
82 

Category 
First category 
Second category 
Third category 

Table 18: Lwot limits. 

Power-to-mass ratio index (PMR)  COP Limit value for Lurban in dB(A) 

PMR ≤ 25 
25 < PMR ≤ 50 
PMR > 50 

74 
75 
78 

Sound levels measured and processed (Lurban and Lwot) used in the original type approval test, 
and mathematically rounded to the nearest integer shall not exceed by more than 3,0 dB(A) 
the values measured and processed at the time of type approval. Furthermore, Lurban shall not 

118 

 
 
 
 
exceed by more than 1,0 dB(A) the limit laid down in Table 16 and Lwot, in connection with 
point 6.2.3 in the regulation., shall not exceed the limit value for Lurban by more than 6,0 dB(A). 

Stationary sound test 

The  vehicle  transmission  shall  be  in  neutral  position  and  the  clutch  engaged,  or  in  parking 
position for automatic transmission, and the parking brake applied for safety, if equipped. 

In case of a two-wheeled motor-driven vehicle having no neutral gear position, measurements 
shall be carried out with the rear wheel raised off the ground so that the wheel can rotate freely. 

The microphone shall be located at a distance of 0,5 ± 0,01 m from the reference point of the 
exhaust pipe defined in Figure 2 and at an angle of 45 ± 5° to the vertical plane containing the 
flow axis of the pipe termination. The microphone shall be at the height of the reference point, 
but not less than 0,2 m from the ground surface. The reference axis of the microphone shall 
lie in a plane parallel to the ground surface and shall be directed towards the reference point 
on the exhaust outlet. 

The reference point shall be the highest point satisfying the following conditions: 

a)  The reference point shall be at the end of the exhaust pipe, 

b)  The reference point shall be on the vertical plane containing the exhaust outlet centre 

and the flow axis of the exhaust pipe termination. 

The target engine speed is defined as 

75 percent of "S" for vehicles with S ≤ 5,000 min−1, and 50 percent of "S" for vehicles with S 
> 5,000 min−1. 

For a vehicle which cannot reach, in a stationary test, the target engine speed defined above, 
95 percent of the maximum engine speed reachable in a stationary test shall be used instead 
as target engine speed. 

Additional Sound Emission Provisions (ASEP) 

ASEP applies to vehicles of category L3 with PMR >50 

Vehicles with variable gear ratios or automatic transmission with non-lockable gear ratios are 
exempted from the requirements of this annex, if the vehicle manufacturer provides technical 
documents to the type approval authority showing, that the vehicle's engine speed at BB' does 
neither  exceed  nBB'  +  0,05  *  (S  –  nidle)  nor  fall  below  nBB'  –  0,05  *  (S  –  nidle)  for  any  test 
condition  inside  the  ASEP  control  range  defined  below,  where  nBB'  is  the  average  engine 
speed at BB' from the three valid full throttle acceleration tests. 

ASEP control range 

The requirements of this annex apply to any vehicle operation with the following restrictions: 

a)  vAA' shall be at least 20 km/h 

b)  vBB' shall not exceed 80 km/h 

c)  nAA' shall be at least 0,1 * (S – nidle) + nidle 

d)  nBB' shall not exceed 

0,85 * (S – nidle) + nidle for PMR < 66 and 

3,4 * PMR-0,33 * (S – nidle) + nidle for PMR > 66 

Note: If the vehicle has more than one gear, the first gear shall not be used 

 
 
 
 
ASEP limits 

Figure 57: R41.04  stationary  noise  measurement  layout. 

The maximum noise level recorded during the passage of the motorcycle through the test track 
shall not exceed: 

Lwot,(i) + (1 * (nPP' – nwot,(i)) / 1,000) + 3 for nPP' < nwot,(i) and 

Lwot,(i) + (5 * (nPP' – nwot,(i)) / 1,000) + 3 for nPP' ≥ nwot,(i) 

Where Lwot,(i) and nPP' have the same meaning as in paragraph 1. of Annex 3 of Regulation 
41.04 and nwot,(i) refers to the corresponding engine speed when the front of the vehicle passes 
the line PP'. 

2.2.1. UN Regulation 41.05 proposal operating conditions 

The full throttle acceleration, constant speed and stationary sound test procedure are exactly 
the same as in the UN Regulation 41.04. Only ASEP test procedure has changed. 

Real Driving Additional Sound Emission Provisions (RD-ASEP)  

The RD-ASEP applies to vehicles of category L3 with PMR >50. RD-ASEP control range 

The requirements of this annex apply to any vehicle operation with the following restrictions: 

a)  vAA' shall be at least 10 km/h 

b)  vBB' shall not exceed 80 km/h for vehicles with PMR≤150 vBB’ shall not exceed 100 km/h 

for vehicles with PMR>150 

c)  nAA' shall be at least 0,1 * (S – nidle) + nidle 

120 

 
 
d)  nBB' shall not exceed 0,8 x S 

Test procedure 

When the front of the  vehicle reaches AA', the throttle shall be fully engaged and held fully 
engaged until the rear of the vehicle reaches BB'. The throttle shall then be returned as quickly 
as possible to the idle position. Pre-acceleration may be used if acceleration is delayed beyond 
AA'. The location of the start of the acceleration shall be reported. 

Test speed and gear selection 

The vehicle shall be tested at each of the following operating conditions: 

I. 

II. 

vPP' = 50 km/h 

The selected gear (i) and pre-acceleration condition shall be the same as those used 
in the original type approval test of Annex 3 of this Regulation. 

III. 

vBB' corresponding to 0,8 x S  

vBB' shall not exceed 80 km/h for vehicles with PMR ≤ 150 or 100 km/h for vehicles with PMR 
> 150. 

The selected gear shall be 2nd. If the 3rd gear satisfies requirements of nBB' and vBB', 3rd shall 
be used. If the 4th gear satisfies requirements of nBB' and vBB', 4th shall be used. If the 5th gear 
satisfies requirements of nBB' and vBB', 5th shall be used. If the 6th gear satisfies requirements 
of nBB' and vBB', 6th shall be used. 

RD-ASEP limits 

The maximum noise level recorded during the passage of the motorcycle through the test track 
shall not exceed: 

Lwot,(i) + (1 * (nPP' – nwot,(i)) / 1,000) + 3 for nPP' < nwot,(i) and 

Lwot,(i) + (5 * (nPP' – nwot,(i)) / 1,000) + 3 for nPP' ≥ nwot,(i) 

Where Lwot,(i) and nPP' have the same meaning as in paragraph 1. of Annex 3 and nwot,(i) refers 
to the corresponding engine speed when the front of the vehicle passes the line PP'. 

If the tests according to Annex 3 of this UN Regulation and the RD-ASEP tests are performed 
with the same vehicle in immediate sequence, the values for Lwot,(i) and nwot,(i) from the Annex 3 
test may be used, if agreed by the type approval authority. Otherwise, when compliance with 
these limits is checked, values for Lwot,(i) and nwot,(i) shall be newly determined by measurements 
as defined in paragraph 1. of Annex 3, however using the same gear (i) and the same pre-
acceleration distance as during type approval. 

Additional operating conditions 

The vehicle shall approach the line AA' at constant speed or in acceleration or deceleration, 
according to the throttle operation which may be requested by the technical service responsible 
for conducting approval tests in agreement with the type approval authorities. 

The approach velocity shall be chosen as such that the vehicle reaches a prescribed test speed 
vtest +/- 5 km/h when its front passes the line AA'. 

[Examples: 

requested vtest=10km/h → valid vAA’=10-15km/h  

requested vtest=15km/h → valid vAA’=10-20km/h  

requested vtest=75km/h → valid vAA’=70-80km/h  

requested vtest=95km/h → valid vAA’=90-100km/h  

requested vtest=100km/h → valid vAA’=95-100km/h] 

 
 
When the front of the vehicle passes the line AA' the throttle control shall be adjusted as rapidly 
as possible to a position (partial throttle, wide open throttle or maintain present throttle control 
position) which may be defined by the technical service responsible for conducting approval 
tests in agreement with the type approval authorities and shall be kept in this position until the 
rear of the vehicle passes line BB’. 

When the  rear  of  the  vehicle  passes  line  BB'  the  throttle control  shall  be  shifted  to  the  idle 
position as rapidly as possible. 

The throttle position between lines AA’ and BB’ shall not result in a deceleration of the vehicle. 

Test speed, gear and mode selection and throttle operation 

The  conditions  of  this  paragraph  may  be  defined  by  the  technical  service  responsible  for 
conducting the approval tests in agreement with the type approval authorities. 

The test speed vtest may be any speed within the RD-ASEP control range as defined below: 

a)  vAA' shall be at least 10 km/h 

b)  vBB' shall not exceed 80 km/h for vehicles with PMR≤150 vBB’ shall not exceed 100 km/h 

for vehicles with PMR>150 

c)  nAA' shall be at least 0,1 * (S – nidle) + nidle 

d)  nBB' shall not exceed 0,8 x S 

The vehicle may be tested in any of the available gears, including 1st gear. 

The vehicle may be tested in any of the available user selectable software programs or modes 
which affect the sound emissions of the vehicle. 

The throttle operation shall be according to the throttle operation which may be requested by 
the  technical  service  responsible  for  conducting  approval  tests  in  agreement  with  the  type 
approval authorities. 

The  throttle  operation  before  line  AA’  and  between  lines  AA’  and  BB’  shall  be  defined  and 
described in a way that it can be performed by a skilled rider who has made himself familiar 
with the riding characteristics of the test vehicle and that the correct execution can be assessed 
by observation without the necessity of technical equipment on the vehicle or at the test site 
other than the equipment which is required for the tests according to Annex 3 of UN Regulation 
41.05. 

If the requested operating conditions lead to an unusual vehicle behaviour (i.e. front wheel lift 
up, apparent wheel spin, chain slap, engine lugging) or any other riding condition which may 
not  be  expected  to  occur  when  the  vehicle  is  operated  in  real  traffic,  that  test  run  shall  be 
discarded. 

2.2.2. UN Regulation 09.08 operating conditions 

The  vehicle  shall  approach  line  AA'  at  a  steady  vehicle  speed  vAA’  corresponding  either,  in 
terms of engine speed, to 75% of the rated engine speed or to 75% of the maximum engine 
speed permitted by the governor or to 50 km/h, whichever is the lowest. 

Acceleration at wide-open-throttle test (WOT) between lines AA’ and BB’. Release of throttle 
after vehicle passing line BB’. The determination of the approach vehicle speed and the gear 
use depends on the transmission type. 

A vehicle with no gearbox shall approach line AA' at a steady vehicle speed vAA’ corresponding 
either, in terms of engine speed, (min-1) to 75% of the rated engine speed or to 75% of the 
maximum engine speed permitted by the governor or to 50 km/h, whichever is the lowest. 

Vehicles  with  manual  transmissions,  automatic  transmissions,  or  transmissions  with 
continuously variable transmission ratios (CVT) tested with locked gears are tested as follows: 

122 

 
If the vehicle is fitted with a dual mode transmission (e.g. low and high), the mode for normal 
on-road operation shall be selected. 

If the vehicle is fitted with a gearbox with two or three or four forward gears or the same number 
of lockable gears in automatic transmission or in CVT, the second gear shall be used. If the 
gearbox has more than four forward gears or the same number of lockable gears in automatic 
transmission or in CVT, the third gear shall be used. 

If,  by  following  the  above  procedure,  the  engine  speed  nBB’,  achieved  when  the  rear  of  the 
vehicle passes the line BB’, exceeds the rated engine speed, the first higher gear (or locked 
gear) which ensures that the rated engine speed is no longer exceeded up to the line BB' of 
the measurement area should be used instead of the second or third gear. 

Vehicles with automatic transmissions, adaptive transmissions or transmissions with variable 
transmission ratios tested with non-locked gears are tested as follows: 

The  gear  selector  position  for  full  automatic  operation  shall  be  used.  Where  several  full 
automatic operation modes are available (e.g. economic, sporty), that mode shall be selected 
which results in the highest average acceleration of the vehicle between lines AA' and BB'. 

The test may then include a gear change to a lower gear and a higher acceleration. A gear 
change to a higher gear and a lower acceleration is not allowed. In any case, a gear change 
to a gear which is typically not used at the specified condition in urban traffic shall be avoided. 

The vehicle shall approach the line AA' at a steady vehicle speed vAA’ of 50 km/h or at 75% of 
its maximum vehicle speed as defined in paragraph 2.10 of this Regulation, whichever is the 
lower. 

Sound level limits 

For L5e, L6e and L7e vehicle categories, sound level limit is 80 dB(A). 

For COP (conformity of production) tests results cannot exceed by more than 3 dB(A) the value 
measured on the homologation, nor by more than 1 dB(A) the sound level limit of 80 dB(A). 

Stationary sound test 

Before  the  measurements  are  started,  the  vehicle  engine  shall  be  brought  to  its  normal 
operating temperature. If the vehicle is equipped with automatic fans, no adjustment shall be 
made to them during the measurement of the sound level. 

While measurements are being made, the gear lever shall be in neutral. If the transmission 
cannot be disconnected, the drive wheel of the vehicle should be allowed to run under no-load 
conditions by, for example, placing the vehicle on a support or on rollers. 

The engine speed shall be held steady at one of the following values: 50 per cent of nrated if 
nrated exceeds 5,000 min-1 

75 per cent of nrated if nrated does not exceed 5,000 min-1 

Where nrated is the rated engine speed as defined in paragraph 2.4 of this Regulation. 

For a vehicle which cannot reach, in a stationary test, the target engine speed defined above, 
95 per cent of the maximum engine speed reachable in a stationary test shall be used instead 
as target engine speed. 

At least three measurements shall be made at each measurement point. The measurements 
shall  be  considered  valid  only  if  the  difference  between  the  results  of  three  consecutive 
measurements is not more than 2 dB(A). 

The microphone shall be located at a distance of 0,5 ± 0.01 m from the reference point of the 
exhaust pipe defined in Figure 56 and at an angle of 45 ± 5° to the vertical plane containing 
the flow axis of the pipe termination. The microphone shall be at the height of the reference 
point, but not less than 0,2 m from the ground surface. The reference axis of the microphone 

 
 
shall lie in a plane parallel to the ground surface and shall be directed towards the reference 
point on the exhaust outlet. 

Figure 58: R09.08  stationary  noise  measurement  layout. 

Additional Sound Emission Provisions (ASEP)  

ASEP applies to vehicles L5category with PMR >50 

Vehicles with variable gear ratios or automatic transmission with non-lockable gear ratios are 
exempted from the requirements of this annex, if the vehicle manufacturer provides technical 
documents to the type approval authority showing, that the vehicle's engine speed at BB' does 
neither exceed 1,15*nBB'_ref nor fall below 0,85* nBB'_ref for any test condition inside the ASEP 
control range defined below, where nBB' is the average engine speed at BB' from the three 
valid full throttle acceleration tests. 

The requirements of this Annex apply to any vehicle operation with the following restrictions: 

a)  vAA' shall be at least 20 km/h 

b)  vBB' shall not exceed 80 km/h 

c)  nAA' shall be at least 0.1 * (nrated – nidle) + nidle, 

d)  nBB' shall not exceed nBB’_max,  

nBB’_max shall be determined by 

I. 

0,85 * (nrated – nidle) + nidle for PMR < 66 and 

3,4 * PMR-0,33 * (nrated – nidle) + nidle for PMR > 66, or 

II. 

1,3* nBB’_ref, 

whichever is higher but shall not exceed nrated. ASEP limits 

The maximum noise level recorded during the passage of the motorcycle through the test track 
shall not exceed: 

Lref + (1 * (nBB' – nBB’_ref) / 1,000) + 3 for nBB' < nBB’_ref and Lref + (5 * (nBB' – nBB’_ref) / 1,000) + 3 
for nBB' ≥ nBB’_ref 

with Lref and nBB’_ref as specified below: 

Lref is the final result from the full throttle acceleration test. The final test result is the average 
of  the  four  test  results  rounded  off  to  the  nearest  whole  decibel.  If  the  figure  following  the 

124 

 
 
decimal point is between 0 and 4, the total is rounded down and if it is between 5 and 9, it is 
rounded up. 

nBB’_ref is the nBB’ values of the measurements averaged and rounded to the nearest integer. 

2.3. Testing results 

2.3.1. UN Regulation 41.04 

Table 19: Sound level test results summary. 

*  Includes sub-subcategory 

** This limit is increased in 1 dB(A) in case of COP. See item 8.3 of the Regulation. 

1PMR< 50, ASEP does not apply. See Annex 7, item 1.1 of the Regulation. 

2CVT's are exempted from this requirement. See Annex 7, item 1.2 of the Regulation 

  L 

urban 

limit ** 

74 

74 

74 

74 

77 
77 
77 
77 
77 
77 
77 
77 
77 
77 

Lstationary 

LASEP 

Limit ASEP ** 

79,6 

81,3 

86,7 

80 

85,8 
93 
91,7 
89,6 
92,4 
90,2 
91,2 
96,9 
98,3 
93,3 

N.A.1 
N.A.1 
N.A.1 
N.A.1 
N.A.2 
85,2 
84,5 
82,6 
85,7 
84,8 
83,5 
86,0 
87,6 
82,2 

N.A.1 
N.A.1 
N.A.1 
N.A.1 
N.A.2 
89,3 
89,2 
87,3 
89,6 
87,3 
88,4 
87,7 
93,9 
88,1 

Type of vehicle 

Urban Scooter 

Enduro 

TRIAL 

Sport 

Urban Scooter 
Touring 
Sport TRAIL 
Sport Naked 
Sport TRAIL 
Sport TRAIL 
Custom 
Sport 
Sport Naked 
Sport TRAIL 

Category and 
sub-category 

L3e-A1 

L3e-A1 
L3e-A2T* 
L3e-A1 

L3e-A2 
L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 

PMR 

38,0 

38,9 

48,4 

49,0 

76,0 
196,0 
230,8 
237,0 
238,1 
241,0 
291,0 
311,0 
331,0 
391,8 

Lwot 

78,3 

76,2 

76,4 

72,4 

76,5 
78,6 
80,7 
77,2 
81,0 
78,5 
78,6 
80,4 
80,2 
81,1 

Lcrs 

69,1 

67,7 

70,2 

67,5 

68,4 
69,2 
68,9 
69,8 
68,6 
72,1 
70,3 
71,7 
72,5 
71,9 

Lurban 

74,7 

74,2 

74,7 

71,1 

71,8 
74 
74,7 
73,5 
74,7 
75,2 
74,7 
76,2 
76,4 
76,3 

Figure 59: Test results vs limits PMR < 50. 

 
 
 
 
 
Figure 60: Test results vs limits PMR > 50. 

Table 20: dB(A) difference between Lurban vs approval Lurban limit of L3e vehicles with PMR 
< 50. 

Type of vehicle 

Sub-category 

Lurban (dB(A)) 

Approval Lurban 
limit (dB(A)) 

dB(A) difference approval 
Lurban limit vs Lurban 

Lurban COP limit 
(dB(A)) 

dB(A) difference Lurban 
COP limit vs Lurban 

Sport 
Enduro 
Urban Scooter 
TRIAL 

L3e-A1 
L3e-A1 
L3e-A1 
L3e-A2T* 

71,1 
74,2 
74,7 
74,7 

74 
74 
74 
74 

2,9 
-0,2 
-0,7 
-0,7 

75 
75 
75 
75 

3,9 
0,8 
0,3 
0,3 

Table 21: dB(A) difference between Lurban vs approval Lurban limit of L3e vehicles with PMR 
> 50. 

Type of vehicle 

Sub-category 

Lurban (dB(A)) 

Approval Lurban 
limit (dB(A)) 

dB(A) difference approval 
Lurban limit vs Lurban 

Lurban COP limit 
(dB(A)) 

dB(A) difference Lurban 

COP limit vs Lurban 

Urban Scooter 
Sport Naked 
Touring 
Sport TRAIL 
Sport TRAIL 
Custom 
Sport TRAIL 
Sport 
Sport TRAIL 
Sport Naked 

L3e-A2 
L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 
L3e-A3 

71,8 
73,5 
74,0 
74,7 
74,7 
74,7 
75,2 
76,2 
76,3 
76,4 

77 
77 
77 
77 
77 
77 
77 
77 
77 
77 

5,2 
3,5 
3,0 
2,3 
2,3 
2,3 
1,8 
0,8 
0,7 
0,6 

78 
78 
78 
78 
78 
78 
78 
78 
78 
78 

6,2 
4,5 
4,0 
3,3 
3,3 
3,3 
2,8 
1,8 
1,7 
1,6 

126 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2.3.2. UN Regulation 09.08 

Table 22: Sound level test results summary. 

*  Includes sub-subcategory 

** This limit is increased in 1 dB(A) in case of COP. See item 8.3 of the Regulation. 

1PMR< 50, ASEP does not apply. See Annex 7, item 1.1 of the Regulation. 

2CVT's are exempted from this requirement. See Annex 7, item 1.2 of the Regulation 

Type of vehicle 

Unbodied 

Bodied Tricycle 

Bodied 

ATV 

Category and 
sub-category 

L5e-A 

L5e-B 

L6e-BP* 

L7e-B1* 

PMR 

Result 

Limit ** 

Lstationary 

92,0 

13,8 

1,1 

53,0 

78,1 

73,2 

77,2 

80 

80 

80 

80 

80 

90,9 

86,7 

79,9 

82,9 

LASEP 

N.A.2 

N.A.1 

N.A.1 

N.A.2 

Figure 61: Test results vs limits. 

Table 23: dB(A) difference between test result vs approval limit of L5e, L6e and L7e 
vehicles. 

*  Includes sub-subcategory 

Type of vehicle 

Sub-category 

Test result 
(dB(A)) 

Approval limit 
(dB(A)) 

dB(A) difference approval 
limit vs test result 

COP limit 
(dB(A)) 

dB(A) difference COP 
limit vs test result 

Unbodied 
Bodied tricycle 
Bodied 
ATV 

L5e-A 
L5e-B 
L6e-BP* 
L7e-B1* 

78,1 
73,2 
77,2 
80,0 

80 
80 
80 
80 

1,9 
6,8 
2,8 
0,0 

81 
81 
81 
81 

2,9 
7,8 
3,8 
1,0 

 
 
 
 
 
 
 
 
 
 
2.3.3. UN Regulation 41.05 

Detailed test data of the RD ASEP measurements for each of the tested vehicles: 

Sport TRAIL (Manual gearbox) 

Gear 

2 

Meas. 1 

Meas. 2 

Meas. 3 

Engine speed aver. 

VAA'' 

Km/h 

58,6 

61,9 

58,8 

59,8 

nAA' 

rpm 

4180 

4416 

4192 

4263 

Remark 6: It shall be 3 consecutive measurements within 2.0 dB(A) . 

INTERPRETATION 

VPP' 

Km/h 

70,9 

74,4 

71,4 

72,2 

VPP' 

Km/h 

80,7 

90,2 

97,6 

5071 

2676 

80,1 

95,1 

VAA'' 

Km/h 

72,8 

82,6 

97,4 

nAA' 

rpm 

4052 

4598 

5308 

Meas. 1 

Meas. 2 

Meas. 3 

4492 

2676 

80,1 

87,1 

92,2 

VAA'' 

Km/h 

89,5 

70,2 

98,6 

5022 

2676 

80,1 

90,5 

94,8 

nAA' 

rpm 

3600 

2676 

3840 

5300 

2676 

80,1 

79,8 

96,2 

VPP' 

Km/h 

93,9 

75,2 

98,1 

Meas. 1 

Meas. 2 

Meas. 3 

3692 

2676 

80,1 

85,6 

88,2 

VAA'' 

Km/h 

16,9 

20,9 

20,9 

3015 

2676 

80,1 

83,9 

84,8 

nAA' 

rpm 

1819 

2157 

2283 

3848 

2676 

80,1 

77,2 

89,0 

VPP' 

Km/h 

30,6 

44,2 

42,3 

Meas. 1 

Meas. 2 

Meas. 3 

3204 

2676 

80,1 

73,7 

85,7 

VAA'' 

Km/h 

55,2 

99,0 

89,9 

4674 

2676 

80,1 

84,3 

93,1 

nAA' 

rpm 

1928 

3541 

3211 

4388 

2676 

80,1 

80,2 

91,7 

VPP' 

Km/h 

61,2 

98,9 

94,2 

ASEP Test (ii) 

nPP' 
rpm 

5060 

5080 

5071 

5071 

VBB' 
Km/h 

84,9 

86,3 

85,1 

85,4 

nBB' 

rpm 

6056 

6110 

6070 

6079 

Lasep,i 

Noise dB(A) 

Rounded 

Left 

89,9 

90,4 

91,2 
AA-BB aasep (i) 

Left 

Right 

Right 

91 

92,3 

93 

7,19 

89,5 

91,1 

Left 

88,9 

89,4 

90,2 

m/s 

dB (A) 

dB (A) 

Right 

90,0 

91,3 

92,0 

awot 

AA'-PP' 

7,28 

6,97 

7,31 

Lasep (side) max dB (A) 

91,1 

RD ASEP - additional operating condition 1 

nPP' 

rpm 

4492 

5022 

5300 

VBB' 

Km/h 

90,1 

99,0 

97,5 

nBB' 

rpm 

5014 

5512 

5300 

Noise dB(A) 

Rounded 

Left 

86,2 

90,3 

80,2 

Right 

88,1 

91,5 

80,8 

Left 

85,2 

89,3 

79,2 

Right 

87,1 

90,5 

79,8 

awot 

AA'-PP' 

5,43 

5,75 

0,02 

Procedure 
carried out 

3rd gear. Full throttle. Speed at V   : 90 km/h 

BB' 

3rd gear. Full throttle. Speed at V   : 99 km/h 

BB' 

3rd gear. Constant speed: 97 km/h 

RD ASEP - additional operating condition 2 

nPP' 
rpm 

3692 

3015 

3848 

VBB' 
Km/h 

98,7 

81,5 

98,3 

nBB' 

rpm 

3888 

3000 

3848 

Noise dB(A) 

Rounded 

awot 

Left 

84,4 

82,6 

77,9 

Right 

86,6 

84,9 

78,2 

Left 

83,4 

81,6 

76,9 

Right 

AA'-PP' 

85,6 

83,9 

77,2 

3,34 

3,33 

-0,12 

Procedure 
carried out 

5th gear. Full throttle. Speed at V   : 99 km/h 

BB' 

5th gear. Full throttle. Speed at V   : 70 km/h 

AA' 

5th gear. Constant speed: 98 km/h 

RD ASEP - additional operating condition 3 

nPP' 
rpm 

3204 

4674 

4388 

VBB' 
Km/h 

39,6 

58,8 

54,0 

nBB' 

rpm 

4127 

6113 

5717 

Noise dB(A) 

Rounded 

awot 

Left 

72,6 

82,6 

80 

Right 

74,7 

85,3 

81,2 

Left 

71,6 

81,6 

79 

Right 

AA'-PP' 

73,7 

84,3 

80,2 

2,47 

5,82 

4,78 

Procedure 
carried out 

1st gear. 1/4 throttle. Speed at V   :  16 km/h 

AA' 

1st gear. 1/2 throttle. Engine speed at V   : 2200 min-1 

BB' 

1st gear. Constant speed: 55 km/h 

RD ASEP - additional operating condition 4 

nPP' 

rpm 

2212 

3534 

3365 

VBB' 

Km/h 

67,8 

99,0 

98,9 

nBB' 

rpm 

2485 

3544 

3884 

Noise dB(A) 

Rounded 

Left 

82,8 

78,5 

84,6 

Right 

84,2 

78,5 

86,9 

Left 

81,8 

77,5 

83,6 

Right 

83,2 

77,5 

85,9 

awot 

AA'-PP' 

3,01 

0,00 

3,28 

Average nPP' asep' 
Average nwot 
Lwot 
Lasep  MAX 

Gear 

3 

Meas. 1 

Meas. 2 

Meas. 3 

INTERPRETATION 
Average nPP' asep' 
Average nwot 
Lwot 
Lasep  (side) max dB(A) 
Lasep  MAX 

Gear 

5 

Meas. 1 

Meas. 2 

Meas. 3 

INTERPRETATION 
Average nPP' asep' 
Average nwot 

Lwot 
Lasep  (side) max dB(A) 
Lasep  MAX 

Gear 

1 

Meas. 1 

Meas. 2 

Meas. 3 

INTERPRETATION 
Average nPP' asep' 
Average nwot 

Lwot 
Lasep  (side) max dB(A) 
Lasep  MAX 

Gear 

6 

Meas. 1 

Meas. 2 

Meas. 3 

INTERPRETATION 
Average nPP' asep' 
Average nwot 
Lwot 
Lasep  (side) max dB(A) 
Lasep  MAX 

Meas. 1 

Meas. 2 

Meas. 3 

2212 

2676 

80,1 

83,2 

82,6 

3534 

2676 

80,1 

77,5 

87,4 

3365 

2676 

80,1 

85,9 

86,5 

Procedure 
carried out 

6th gear. Full throttle. Speed at V   : 56 km/h 

AA' 

6th gear. Constant speed: 99 km/h 

6th gear. Full throttle. Speed at V   : 90 km/h 

AA' 

128 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Sport  

Gear 

2 

Meas. 1 

Meas. 2 

Meas. 3 

Engine speed aver. 

VAA'' 

Km/h 

59,0 

59,1 

59,9 

59,3 

nAA' 

rpm 

3160 

3168 

3208 

3179 

Remark 6: It shall be 3 consecutive measurements within 2.0 dB(A) . 

INTERPRETATION 

ASEP Test (ii) 

VPP' 

Km/h 

74,9 

75,9 

76,0 

75,6 

nPP' 
rpm 

4016 

4066 

4074 

4052 

VBB' 
Km/h 

90,1 

90,3 

91,4 

90,6 

nBB' 

rpm 

4830 

4839 

4896 

4855 

Lasep,i 

Noise dB(A) 

Rounded 

awot 

Left 

88,9 

88,5 

88,7 
AA-BB aasep (i) 

Left 

Right 

Right 

88,5 

89,2 

89,2 

8,09 

87,7 

88,0 

Left 

87,9 

87,5 

87,7 

m/s 

dB (A) 

dB (A) 

Right 

AA'-PP' 

87,5 

88,2 

88,2 

8,02 

8,04 

8,22 

Lasep (side) max dB (A) 

88,0 

Average nPP' asep' 
Average nwot 
Lwot 
Lasep  MAX 

Gear 

3 

Meas. 1 

Meas. 2 

Meas. 3 

INTERPRETATION 
Average nPP' asep' 
Average nwot 

Lwot 
Lasep  (side) max dB(A) 
Lasep  MAX 

Gear 

5 

Meas. 1 

Meas. 2 

Meas. 3 

INTERPRETATION 
Average nPP' asep' 
Average nwot 

Lwot 
Lasep  (side) max dB(A) 
Lasep  MAX 

Gear 

6 

Meas. 1 

Meas. 2 

Meas. 3 

INTERPRETATION 
Average nPP' asep' 
Average nwot 

Lwot 
Lasep  (side) max dB(A) 
Lasep  MAX 

Gear 

1 

Meas. 1 

Meas. 2 

Meas. 3 

4052 

1636 

80,4 

95,5 

VAA'' 

Km/h 

42,8 

82,0 

60,3 

RD ASEP - additional operating condition 1 

nAA' 

rpm 

1762 

3376 

2485 

VPP' 

Km/h 

56,7 

81,5 

72,7 

nPP' 
rpm 

2333 

3357 

2992 

VBB' 
Km/h 

72,4 

81,7 

86,1 

nBB' 

rpm 

2980 

3363 

3547 

Noise dB(A) 

Rounded 

awot 

Left 

84,5 

77,9 

86,9 

Right 

85,6 

80,1 

88,1 

Left 

83,5 

76,9 

85,9 

Right 

AA'-PP' 

84,6 

79,1 

87,1 

5,88 

-0,09 

6,52 

Meas. 1 

Meas. 2 

Meas. 3 

2333 

1636 

80,4 

84,6 

86,9 

VAA'' 

Km/h 

70,9 

81,0 

94,5 

3357 

1636 

80,4 

79,1 

92,0 

nAA' 

rpm 

2008 

2293 

2675 

2992 

1636 

80,4 

87,1 

90,2 

VPP' 

Km/h 

77,3 

86,7 

95,5 

Meas. 1 

Meas. 2 

Meas. 3 

2188 

1636 

80,4 

83,2 

86,2 

VAA'' 

Km/h 

71,4 

80,8 

90,3 

2454 

1636 

80,4 

85,3 

87,5 

nAA' 

rpm 

1742 

1972 

2204 

2704 

1636 

80,4 

78,5 

88,7 

VPP' 

Km/h 

76,5 

85,5 

94,8 

Meas. 1 

Meas. 2 

Meas. 3 

1866 

1636 

80,4 

81,2 

84,6 

VAA'' 

Km/h 

16,7 

68,8 

40,6 

2086 

1636 

80,4 

82,3 

85,7 

nAA' 

rpm 

1163 

4784 

2821 

2313 

1636 

80,4 

84,7 

86,8 

VPP' 

Km/h 

48,2 

69,0 

41,1 

Procedure 
carried out 

3rd gear. Full throttle. Speed at V   : 72 km/h 

BB' 

3rd gear. Constant speed: 82 km/h 

3rd gear. Full throttle. Speed at V   : 86 km/h 

BB' 

RD ASEP - additional operating condition 2 

nPP' 
rpm 

2188 

2454 

2704 

VBB' 
Km/h 

84,0 

93,5 

95,8 

nBB' 

rpm 

2379 

2646 

2713 

Noise dB(A) 

Rounded 

awot 

Left 

82,7 

86,3 

77,1 

Right 

84,2 

84,5 

79,5 

Left 

81,7 

85,3 

76,1 

Right 

AA'-PP' 

83,2 

83,5 

78,5 

3,51 

3,76 

0,44 

Procedure 
carried out 

5th gear. Full throttle. Speed at V   : 71 km/h 

AA' 

5th gear. Full throttle. Speed at V   : 94 km/h 

BB' 

5th gear. Constant speed: 95 km/h 

RD ASEP - additional operating condition 3 

nPP' 
rpm 

1866 

2086 

2313 

VBB' 
Km/h 

81,4 

90,9 

98,5 

nBB' 

rpm 

1985 

2218 

2404 

Noise dB(A) 

Rounded 

Left 

82,2 

82,4 

84 

Right 

81,4 

83,3 

85,7 

Left 

81,2 

81,4 

83,0 

Right 

80,4 

82,3 

84,7 

awot 

AA'-PP' 

2,63 

2,99 

2,67 

Procedure 
carried out 

6th gear. Full throttle. Speed at V   : 71 km/h 

AA' 

6th gear. Full throttle. Speed at V   : 81 km/h 

AA' 

6th gear. Full throttle. Speed at V   : 90 km/h 

AA' 

RD ASEP - additional operating condition 4 

nPP' 
rpm 

3352 

4801 

2861 

VBB' 
Km/h 

70,1 

69,5 

41,6 

nBB' 

rpm 

4877 

4836 

2893 

Noise dB(A) 

Rounded 

awot 

Left 

87,6 

84,3 

74,4 

Right 

87,4 

85,7 

76,2 

Left 

86,6 

83,3 

73,4 

Right 

AA'-PP' 

86,4 

84,7 

75,2 

8,00 

0,18 

0,15 

INTERPRETATION 
Average nPP' asep' 
Average nwot 

Lwot 
Lasep  (side) max dB(A) 

Meas. 1 

Meas. 2 

Meas. 3 

3352 

1636 

80,4 

86,6 

4801 

1636 

80,4 

84,7 

2861 

1636 

80,4 

75,2 

Procedure 
carried out 

Sport TRAIL (Automatic gearbox) 

1st gear. Full throttle. Speed at V   : 16 km/h 

AA' 

1st gear. Constant speed: 69 km/h 

1st gear. Constant speed: 41 km/h 

Gear 

2 

Meas. 1 

Meas. 2 

Meas. 3 

Engine speed aver. 

VAA'' 

Km/h 

58,4 

58,6 

58,4 

58,5 

nAA' 

rpm 

4165 

4177 

4168 

4170 

Remark 6: It shall be 3 consecutive measurements within 2.0 dB(A) . 

INTERPRETATION 

Average nPP' asep' 
Average nwot 
Lwot 
Lasep  MAX 

5075 

2749 

82,2 

96,8 

ASEP Test (ii) 

VPP' 

Km/h 

71,1 

70,9 

71,5 

71,1 

nPP' 
rpm 

5072 

5054 

5097 

5075 

VBB' 
Km/h 

84,6 

84,7 

85,1 

84,8 

nBB' 

rpm 

6038 

6040 

6070 

6049 

Lasep,i 

Noise dB(A) 

Rounded 

awot 

Left 

89,9 

90,3 

90,9 
AA-BB aasep (i) 

Left 

Right 

Right 

91,5 

91,8 

93,1 

7,28 

89,4 

91,1 

Left 

88,9 

89,3 

89,9 

m/s 

dB (A) 

dB (A) 

Right 

AA'-PP' 

90,5 

90,8 

92,1 

7,24 

7,22 

7,38 

Lasep (side) max dB (A) 

91,1 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Gear 

3 

Meas. 1 

Meas. 2 

Meas. 3 

VAA'' 

Km/h 

75,6 

95,2 

35,4 

nAA' 

rpm 

4207 

5297 

1971 

VPP' 

Km/h 

83,3 

95,7 

49,3 

nPP' 
rpm 

4635 

5327 

2745 

VBB' 
Km/h 

91,9 

95,8 

61,9 

nBB' 

rpm 

5117 

5334 

3445 

Noise dB(A) 

Rounded 

awot 

Left 

86 

80 

80,9 

Right 

87,8 

80,5 

83,1 

Left 

85,0 

79,0 

79,9 

Right 

AA'-PP' 

86,8 

79,5 

82,1 

5,28 

0,24 

4,97 

RD ASEP - additional operating condition 1 

INTERPRETATION 
Average nPP' asep' 
Average nwot 

Lwot 
Lasep  (side) max dB(A) 
Lasep  MAX 

Gear 

5 

Meas. 1 

Meas. 2 

Meas. 3 

INTERPRETATION 
Average nPP' asep' 
Average nwot 

Lwot 
Lasep  (side) max dB(A) 
Lasep  MAX 

Gear 

1 

Meas. 1 

Meas. 2 

Meas. 3 

INTERPRETATION 
Average nPP' asep' 
Average nwot 

Lwot 
Lasep  (side) max dB(A) 
Lasep  MAX 

Gear 

6 

Meas. 1 

Meas. 2 

Meas. 3 

INTERPRETATION 
Average nPP' asep' 
Average nwot 
Lwot 

Lasep  (side) max dB(A) 

Meas. 1 

Meas. 2 

Meas. 3 

4635 

2749 

82,2 

86,8 

94,6 

VAA'' 

Km/h 

84,8 

70,0 

95,2 

5327 

2749 

82,2 

79,5 

98,1 

nAA' 

rpm 

3340 

2757 

3751 

2745 

2749 

82,2 

82,1 

85,2 

VPP' 

Km/h 

89,3 

75,5 

95,5 

Meas. 1 

Meas. 2 

Meas. 3 

3517 

2749 

82,2 

83,7 

89,0 

VAA'' 

Km/h 

20,6 

59,9 

25,0 

2975 

2749 

82,2 

83,0 

86,3 

nAA' 

rpm 

2141 

6210 

2591 

3761 

2749 

82,2 

77,0 

90,3 

VPP' 

Km/h 

51,2 

60,2 

25,1 

Meas. 1 

Meas. 2 

Meas. 3 

5311 

2749 

82,2 

93,2 

98,0 

VAA'' 

Km/h 

55,9 

87,8 

89,1 

6240 

2749 

82,2 

81,9 

102,7 

nAA' 

rpm 

1998 

3137 

3182 

2603 

2749 

82,2 

67,2 

85,1 

VPP' 

Km/h 

61,5 

88,6 

93,6 

Meas. 1 

Meas. 2 

Meas. 3 

2199 

2749 

82,2 

81,2 

3167 

2749 

82,2 

76,2 

nAA' 

rpm 

6567 

6610 

6636 

6605 

Sport TRAIL 

Gear 

2 

Meas. 1 

Meas. 2 

Meas. 3 

Engine speed aver. 

VAA'' 

Km/h 

73,5 

74,0 

74,3 

73,9 

Remark 6: It shall be 3 consecutive measurements within 2.0 dB(A) . 

INTERPRETATION 

Average nPP' asep' 
Average nwot 
Lwot 
Lasep  MAX 

Gear 

3 

Meas. 1 

Meas. 2 

Meas. 3 

7492 

2936 

81,1 

106,9 

VAA'' 

Km/h 

80,7 

98,2 

33,8 

nAA' 

rpm 

5728 

6974 

2400 

3343 

2749 

82,2 

84,2 

VPP' 

Km/h 

83,3 

84,1 

84,2 

83,9 

VPP' 

Km/h 

89,7 

98,4 

48,4 

Procedure 
carried out 

3rd gear. Full throttle. Speed at V   : 90 km/h 

BB' 

3rd gear. Constant speed: 95 km/h 

3rd gear. Full throttle. Speed at V   : 35 km/h 

AA' 

RD ASEP - additional operating condition 2 

nPP' 
rpm 

3517 

2975 

3761 

VBB' 
Km/h 

94,2 

81,7 

95,4 

nBB' 

rpm 

3711 

3218 

3760 

Noise dB(A) 

Rounded 

awot 

Left 

83,1 

82,4 

77,8 

Right 

84,7 

84 

78 

Left 

82,1 

81,4 

76,8 

Right 

AA'-PP' 

83,7 

83,0 

77,0 

3,26 

3,42 

0,08 

Procedure 
carried out 

5th gear. Full throttle. Speed at V   : 94 km/h 

BB' 

5th gear. Full throttle. Speed at V   : 70 km/h 

AA' 

5th gear. Constant speed: 98 km/h 

RD ASEP - additional operating condition 3 

nPP' 
rpm 

5311 

6240 

2603 

VBB' 
Km/h 

64,2 

59,9 

24,9 

nBB' 

rpm 

6655 

6216 

2586 

Noise dB(A) 

Rounded 

Left 

91,7 

82,5 

66,7 

Right 

94,2 

82,9 

68,2 

Left 

90,7 

81,5 

65,7 

Right 

93,2 

81,9 

67,2 

awot 

AA'-PP' 

7,12 

0,01 

0,00 

Procedure 
carried out 

1st gear. 1/2 throttle. Speed at V   :  20 km/h 

AA' 

1st gear. Constant speed: 60 km/h 

1st gear. Constant speed: 25 km/h 

RD ASEP - additional operating condition 4 

nPP' 
rpm 

2199 

3167 

3343 

VBB' 
Km/h 

68,5 

89,4 

97,5 

nBB' 

rpm 

2448 

3192 

3483 

Noise dB(A) 

Rounded 

awot 

Left 

81,2 

77,1 

84,7 

Right 

82,2 

77,2 

85,2 

Left 

80,2 

76,1 

83,7 

Right 

AA'-PP' 

81,2 

76,2 

84,2 

3,03 

0,52 

3,03 

Procedure 
carried out 

6th gear. Full throttle. Speed at V   : 56 km/h 

AA' 

6th gear. Full throttle. Speed at V   : 85 km/h 

AA' 

6th gear. Full throttle. Speed at V   : 90 km/h 

AA' 

ASEP Test (ii) 

nPP' 
rpm 

7439 

7514 

7522 

7492 

VBB' 
Km/h 

93,0 

94,0 

94,4 

93,8 

nBB' 

rpm 

8306 

8397 

8430 

8378 

Lasep,i 

Noise dB(A) 

Rounded 

awot 

Left 

88,2 

88,3 

88,6 
AA-BB aasep (i) 

Left 

Right 

Right 

88,4 

88,7 

88,8 

5,74 

87,4 

87,6 

Left 

87,2 

87,3 

87,6 

m/s 

dB (A) 

dB (A) 

Right 

AA'-PP' 

87,4 

87,7 

87,8 

5,59 

5,80 

5,84 

Lasep (side) max dB (A) 

87,6 

RD ASEP - additional operating condition 1 

nPP' 
rpm 

6367 

6987 

3436 

VBB' 
Km/h 

99,2 

98,8 

62,1 

nBB' 

rpm 

7045 

7014 

4410 

Noise dB(A) 

Rounded 

awot 

Left 

87,3 

83,3 

81,4 

Right 

87,5 

83,4 

81,5 

Left 

86,3 

82,3 

80,4 

Right 

AA'-PP' 

86,5 

82,4 

80,5 

5,76 

0,20 

4,68 

INTERPRETATION 
Average nPP' asep' 
Average nwot 

Meas. 1 

Meas. 2 

Meas. 3 

6367 

2936 

6987 

2936 

3436 

2936 

3rd gear. Full throttle. Speed at V   : 99 km/h 

BB' 

130 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Lwot 

Lasep  (side) max dB(A) 
Lasep  MAX 

81,1 

86,5 

101,3 

Gear 

5 

Meas. 1 

Meas. 2 

Meas. 3 

VAA'' 

Km/h 

84,8 

47,4 

98,4 

81,1 

82,4 

104,4 

nAA' 

rpm 

4247 

2375 

4929 

81,1 

80,5 

86,6 

VPP' 

Km/h 

91,1 

57,3 

98,2 

INTERPRETATION 
Average nPP' asep' 
Average nwot 

Lwot 
Lasep  (side) max dB(A) 
Lasep  MAX 

Gear 

6 

Meas. 1 

Meas. 2 

Meas. 3 

INTERPRETATION 
Average nPP' asep' 
Average nwot 
Lwot 
Lasep  (side) max dB(A) 
Lasep  MAX 

Gear 

1 

Meas. 1 

Meas. 2 

Meas. 3 

Meas. 1 

Meas. 2 

Meas. 3 

4561 

2936 

81,1 

87,9 

92,2 

VAA'' 

Km/h 

87,8 

98,7 

55,3 

2871 

2936 

81,1 

82,5 

84,0 

nAA' 

rpm 

3763 

4232 

2370 

4921 

2936 

81,1 

79,9 

94,0 

VPP' 

Km/h 

92,3 

99,2 

62,4 

Meas. 1 

Meas. 2 

Meas. 3 

3960 

2936 

81,1 

85,6 

89,2 

VAA'' 

Km/h 

31,1 

21,2 

67,3 

4253 

2936 

81,1 

80,0 

90,7 

nAA' 

rpm 

3801 

2585 

8225 

2678 

2936 

81,1 

83,8 

83,8 

VPP' 

Km/h 

51,9 

45,8 

66,9 

Procedure 
carried out 

3rd gear. Constant speed: 98 km/h 

3rd gear. Full throttle. Speed at V   : 62 km/h 

BB' 

RD ASEP - additional operating condition 2 

nPP' 
rpm 

4561 

2871 

4921 

VBB' 
Km/h 

98,4 

65,4 

98,0 

nBB' 

rpm 

4929 

3277 

4907 

Noise dB(A) 

Rounded 

awot 

Left 

88,9 

83,5 

80,9 

Right 

87,6 

82,9 

80,3 

Left 

87,9 

82,5 

79,9 

Right 

AA'-PP' 

86,6 

81,9 

79,3 

4,31 

3,50 

-0,14 

Procedure 
carried out 

5th gear. Full throttle. Speed at V   : 98 km/h 

BB' 

5th gear. Full throttle. Speed at V   : 47 km/h 

AA' 

5th gear. Constant speed: 98 km/h 

RD ASEP - additional operating condition 3 

nPP' 

rpm 

3960 

4253 

2678 

VBB' 

Km/h 

98,6 

99,7 

70,3 

nBB' 

rpm 

4226 

4273 

3015 

Noise dB(A) 

Rounded 

Left 

86,6 

81 

84,8 

Right 

85,6 

80,6 

84,1 

Left 

85,6 

80,0 

83,8 

Right 

84,6 

79,6 

83,1 

awot 

AA'-PP' 

3,47 

0,33 

3,26 

Procedure 
carried out 

6th gear. Full throttle. Speed at V   : 99 km/h 

BB' 

6th gear. Constant speed: 99 km/h 

6th gear. Full throttle. Speed at V   : 70 km/h 

BB' 

RD ASEP - additional operating condition 4 

nPP' 
rpm 

6345 

5595 

8173 

VBB' 
Km/h 

67,9 

61,7 

67,0 

nBB' 

rpm 

8293 

7540 

8184 

Noise dB(A) 

Rounded 

awot 

Left 

86,3 

84,6 

84,7 

Right 

86,2 

84,6 

85,3 

Left 

85,3 

83,6 

83,7 

Right 

AA'-PP' 

85,2 

83,6 

84,3 

6,28 

5,80 

-0,08 

INTERPRETATION 
Average nPP' asep' 
Average nwot 

Lwot 
Lasep  (side) max dB(A) 

Meas. 1 

Meas. 2 

Meas. 3 

6345 

2936 

81,1 

85,3 

5595 

2936 

81,1 

83,6 

8173 

2936 

81,1 

84,3 

Procedure 
carried out 

1st gear. 1/4 throttle. Speed at V   :  31 km/h 

AA' 

1st gear. 1/2 throttle. Engine speed at V   : 2600 min-1 

BB' 

1st gear. Constant speed: 67 km/h 

2.4. Summary  of  EU  WVTA  results  sampling  per  L-vehicle 

sub-category 

In addition to the measured test results defined for the Task 2 of the study, a review of the 
declared sound level values of a representative number of WVTA has been performed, with 
the following results: 

2.4.1. Average results according to UN Regulation No. 41.04 

Category  No. of samples 

PMR 

Lwot (dB(A))  Lurban (dB(A)) 

L3e-A1 

L3e-A2 

L3e-A3 

2 
13 
23 
2 
41 

> 
50 
25 < PMR < 50 
> 
50 
25 < PMR < 50 
>50 

77,4 
74,4 
77,1 
76,5 
79,3 

75,0 
71,8 
74,6 
73,5 
75,4 

Approval limit 
Lurban (dB(A)) 
77 
74 
77 
74 
77 

dB(A) difference between 
approval limit vs Lurban 
2,0 
2,2 
2,4 
0,5 
1,6 

2.4.2. Average results according to UN Regulation No. 09.08 

Category  No. of samples  Pass-by result (dB(A))  Approval Limit (dB(A)) 

L5e-A 

15 

77,8 

80 

dB(A) difference between 
approval limit vs pass-by result 
2,2 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
L5e-B 
L6e-BP 
L6e-BU 
L7e-B1 
L7e-B2 
L7e-CP 

5 
6 
3 
27 
9 
2 

76,6 
71,5 
70,7 
79,5 
78,8 
71,5 

80 
80 
80 
80 
80 
80 

3,4 
8,5 
9,3 
0,5 
1,2 
8,5 

2.5. Conclusions 

a)  The  obtained  sound  level  test  results  for  the  L3  vehicles  with  PMR  ≤  50  tested  are 

below the COP existing limits. 

b)  The obtained sound level test results for the L3 vehicles with PMR > 50, L5e, L6e and 

L7e vehicles tested are below the approval limits. 

c)  The margin between the measured test results and the existing limits vary depending 

on the vehicle’s subcategory. 

  L3e-A1 and L3e-A2 vehicles with PMR < 50: The sound emission level obtained in 
the tests is near to the approval limit, in some cases exceeding that approval limit, 
but without exceeding the COP limit. 

 

 L3e-A2 and L3e-A3 vehicles with PMR > 50 with medium engine performance: The 
results  achieved  comply  with  the  approval  limits.  A  5  dB(A)  to  2  dB(A)  range 
between the test result and the approval limit. 

  L3e-A3  vehicles  with  PMR  >  50  with  high  engine  performance:  The  difference 

between the test results obtained and the approval limit is 1 dB(A) below. 

  L5e  and  L6e  vehicles:  The  sound  level  limits  are  below  the  approval  limit.  A 

difference from 2 dB(A) to 7 dB(A) below the approval limit. 

  L7e vehicle: There is no difference between the test result and the approval limit. 

Same result obtained as the approval limit. 

d)  Most of the motorcycles tested according to RD-ASEP comply with the limits,.Only one 

case exceeded the limits. 

e)  During the RD-ASEP tests at low nAA’ driving conditions with lower sound emission 
level results, the RD- ASEP limits have been exceeded. However, with a higher nAA’ 
driving conditions the sound emission levels were higher and comply with RD- ASEP 
limits. 

132 

 
 
 
 
3. Noise source ranking 

The objective of Task 3 is to assess the influence of the different systems/sub-systems of the 
L-category vehicles during exterior noise testing. In order to study the potential noise reduction 
of the different systems/sub-systems, a Noise Source Ranking (NSR) testing activity has been 
carried out on the most representative vehicles measured during Task 2. 

3.1. Vehicle’s selection justification 

The vehicle selection has been defined according to the following criteria: 

a)  Vehicles previously selected and tested during Task 2. 

b)  According to Task 1 of this study, test the vehicles perceived as more relevant in terms 

of noise impact on the European public roads. 

c)  Include a wide range of powertrain configurations. 

d)  Represent the current fleet of vehicles in Europe (L3e and L5e sub-categories).. 

Table  24  summarizes  the  vehicles  selected  for  this  study  (6  vehicles  in  total)  and  its 
specifications: 

Table 24: Task 3 vehicle selection 

UN- 
Regulation 

PMR 

Category / 
Sub-category 

Engine 
type 

Gear / 
Transmission 

Target 
specifications 

Name in this report * 

R.41.04 

PMR > 50 

R.09.08 

PMR ≤ 50 
PMR > 50 

L3e-A3 

L3e-A3 

L3e-A3 

L3e-A3 
L5e-B 
L5e-A 

PI 

PI 

PI 

PI 
PI 
PI 

Locked / Manual 

Sport Naked 

Locked / Manual 

Sport TRAIL 

Sport Naked 

Sport TRAIL 

Non-locked / 
Automatic 
Locked / Manual 
Locked / Manual 
Non-locked / CVT 

Sport TRAIL (Automatic) 

Sport TRAIL_Auto 

Sport TRAIL (Manual) 
Bodied Tricycle 
Unbodied Tricycle 

Sport TRAIL_Manual 
Bodied Tricycle 
Unbodied Tricycle 

  Sport naked: Are versatile, general-purpose street motorcycles. They are recognized 
primarily by their upright riding position, partway between the reclining rider posture of 
the  cruisers  and  the  forward  leaning  sport  bikes.  Footpegs  are  below  the  rider  and 
handlebars are high enough to not force the rider to reach too far forward, placing the 
shoulders above the hips in a natural position. Because of their flexibility, lower costs, 
and moderate engine output, standards are particularly suited to motorcycle beginners. 

  Sport  Trail:  Dual-purpose  or  on/off-road  motorcycles  or  adventure  motorcycles,  are 
street  legal  machines  that  are  also  designed  to  enter  off-road  situations.  Typically 
based on a dirt bike chassis, they have added lights, mirrors, signals, and instruments 
that allow them to be licensed for public roads. They are higher than other street bikes, 
with a high center of gravity and tall seat height, allowing good suspension travel for 
rough ground. 

  Unbodied:  Unbodied  tricycle.  A  tilting  three-wheeled  scooter.  It  is  noted  for  its 
combination  of  two  front  wheels  and  a  single  rear  wheel.  General-purpose  city 
motorcycle. 

  Bodied: Bodied tricycle. In Asian and Southeast Asian countries, motorized trikes are 
used as small freight trucks and commercial vehicles. Nicknamed "three-wheelers" or 
"tuk-tuks"  in  popular  parlance,  they  are  a  motorized  version  of  the  traditional  pulled 

 
 
 
 
 
 
 
 
 
 
 
 
rickshaw or cycle rickshaw. While they are mostly used as taxis for hire, they are also 
used for commercial and freight deliveries. They are particularly popular in cities where 
traffic congestion is a problem. 

 

3.2. Testing procedures 

NSR study is based on testing each vehicle according to the testing procedures described in 
the previous task and relative to each vehicle category: 

  L3e (two-wheel motorcycles): UN Regulation 41.04 – Constant speed and acceleration 

test (1 or 2 gears) 

  L5e (tricycles): UN Regulation 9.08 – Acceleration test 

Stationary sound test and Additional Sound Emission Provisions (ASEP) test have not been 
considered for this study. 

Noise  tests  have been  carried  out on  test tracks  certified  according to ISO  10844:2014,  as 
stated in the related regulation. 

NSR  test  is  based  on  the  exterior  noise  sound  level  of  each  vehicle  is  the  sum  of  the 
contribution of different noise sources generated during the test. Masking each one of the noise 
sources, the influence of each source can be determined. For this study, the following noise 
sources have been considered: 

  Exhaust 

  Engine 

  Transmission (gearbox) 

  Driveline (chain and final drive) 

 

Intake 

Each  system/sub-system  has  been  masked  using  different  techniques,  according  its  main 
characteristics. Used techniques are described below: 

  Exhaust 

Exhaust was masked using a “jumbo” or “infinite” muffler. For this study, a passenger vehicle 
muffler was used, covered by rock wool material to minimize exhaust shell noise. 

134 

 
 
 
Figure 62: “Infinite” muffler used for exhaust noise masking. 

  Engine/ Transmission / Driveline 

These parts were masked using specific covers designed for each vehicle. These covers were 
built of different layers: 

-  Rock wool to absorb system noise 

-  Lead (2 mm plate) to minimize sound transmission 

-  Fireproof  polyurethane  foam  to  maintain  all  layers  together  on  its  correct  position 

around each studied system 

For some vehicles and due to the closeness of the different sources, some systems have been 
considered as a unique noise source. 

Figure 63: Example of engine cover. 

 
 
 
 
 
 
 
 
 

Intake 

Intake noise was masked using an “infinite” intake muffler. A specific muffler was designed and 
3-D printed for the L-category vehicles study. 

Figure 64: “Infinite” muffler used for intake noise masking 

For each tested vehicle, every configuration is measured according to the following test plan: 

  Baseline test 

  Full mask test (all systems covered or muffled) 

 

Intake unmuffled 

  Driveline uncovered 

  Transmission uncovered 

  Engine uncovered 

  Exhaust unmuffled – Baseline repetition 

Each configuration is measured separately on all test conditions, i.e. the test is carried out in 
accordance with UN R41 or R9, depending on the L-cat vehicle, and for each component test 
at NSR. A minimum of two runs is measured and analysed per each test condition (mean value 
is  reported).  The  comparison  between  the  noise  level  of  each  configuration  shows  the 
influence of the corresponding systems. 

Noise source contribution results are measured and calculated over test distance (-15 m from 
PP’ line, centre of the test track, to +15 m from PP’ line. AA’ line is placed at -10 m from PP’ 
and BB’ line is placed at +10 m from PP’, see Figure 63). Actual test acquires noise level every 
0.10 m against the vehicle position. 

136 

 
 
 
Figure 65: Testing track and measuring points 

Using  dB  subtractions  of  every  tested  configuration,  individual  contribution  of  each  noise 
system can be calculated (for each test condition). As explained, this calculation is made over 
distance, but focus needs to be placed on the maximum noise level position. At the end, this 
value is the one used for the Lurban level global calculation. 

It needs to be noticed that according UN Regulation 41.04 procedure (L3e category only), Lurban 
calculation is a combination of the maximum sound level measured during acceleration test 
and constant speed test. As described in Task 2 Lurban is defined: 

Lurban = kp * Lcrs + (1 - kp) * Lwot 

For vehicles tested in two gears the partial power factor is defined as  

kp = 1 - (aurban / awot,ref). 

For vehicles tested in a single gear or with the gear selector in one position the partial power 
factor is defined as: 

kp = 1 - (aurban / awot,(i)) 

If awot,(i) is equal to or less than aurban, kp is set to zero. 

Lwot = maximum sound level measured on either side during acceleration test. 

Lcrs = maximum sound level measured on either side during constant speed test 

Both  contributions  (acceleration  and  constant  speed)  must  be  considered  to  assess  sound 
level final possible reduction. 

For  UN  Regulation  9.08  regulation  (L5e,  L6e  and  L7e  vehicle  categories)  only  acceleration 
tests are mandatory. 

 
 
 
 
 
 
 
 
3.3. Results 

3.3.1. Vehicles tested according to the UN Regulation No. 41.04 

L3e-A3 vehicle: Sport TRAIL AUTO 

Constant speed tests – 3rd gear 

In the figures below, the term ‘Baseline’ denotes the initial configuration of the vehicle and the 
term ‘Full masked’ means that all parts checked for SNR are covered. 

Sport TRAIL AUTO 

Figure 66: Baseline versus full mask noise test (Right and Left side). 

. 

138 

 
 
 
 
 
 
 
 
 
Sport TRAIL AUTO 

Figure 67: Noise contribution of each system over distance (Right and Left side). 

Figure 68: Noise contribution of each system at maximum noise level vehicle position. 

 
 
 
 
 
 
 
 
 
Constant speed tests – 4th gear 

Sport TRAIL AUTO 

Figure 69: Baseline versus full mask noise test (Right and Left side). 

140 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Sport TRAIL AUTO 

Figure 70: Noise contribution of each system over distance (Right and Left side). 

Figure 71: Noise contribution of each system at maximum noise level vehicle position. 

 
 
 
 
 
 
 
 
 
Acceleration tests – 3rd gear 

Sport TRAIL AUTO 

Figure 72: Baseline versus full mask noise test (Right and Left side). 

142 

 
 
 
 
 
 
 
Sport TRAIL AUTO 

Figure 73: Noise contribution of each system over distance (Right and Left side). 

Figure 74: Noise contribution of each system at maximum noise level vehicle position. 

 
 
 
 
 
 
 
 
 
Acceleration tests – 4th gear 

Sport TRAIL AUTO 

Figure 75: Baseline versus full mask noise test (Right and Left side). 

144 

 
 
 
 
 
 
 
Sport TRAIL AUTO 

Figure 76: Noise contribution of each system over distance (Right and Left side). 

Figure 77: Noise contribution of each system at maximum noise level vehicle position. 

 
 
 
 
 
 
 
Figure 78: Noise contribution of each system for LUrban of Sport TRAIL AUTO vehicle. 

146 

 
 
 
 
L3e-A3 vehicle: Sport TRAIL MANUAL 

Constant speed tests – 3rd gear 

Sport TRAIL MANUAL 

Figure 79: Baseline versus full mask noise test (Right and Left side). 

 
 
 
 
 
 
 
 
Sport TRAIL MANUAL 

Figure 80: Noise contribution of each system over distance (Right and Left side). 

Figure 81: Noise contribution of each system at maximum noise level vehicle position. 

148 

 
 
 
 
 
 
 
 
Constant speed tests – 4th gear 

Sport TRAIL MANUAL 

Figure 82: Baseline versus full mask noise test (Right and Left side). 

 
 
 
 
 
 
 
 
Sport TRAIL MANUAL 

Figure 83: Noise contribution of each system over distance (Right and Left side). 

Figure 84: Noise contribution of each system at maximum noise level vehicle position. 

150 

 
 
 
 
 
 
 
 
Acceleration tests – 3rd gear 

Sport TRAIL MANUAL 

Figure 85: Baseline versus full mask noise test (Right and Left side). 

 
 
 
 
 
 
 
 
 
Sport TRAIL MANUAL 

Figure 86: Noise contribution of each system over distance (Right and Left side). 

Figure 87: Noise contribution of each system at maximum noise level vehicle position. 

152 

 
 
 
 
 
 
 
 
Acceleration tests – 4th gear 

Sport TRAIL MANUAL 

Figure 88: Baseline versus full mask noise test (Right and Left side). 

 
 
 
 
 
 
 
 
Sport TRAIL MANUAL 

Figure 89: Noise contribution of each system over distance (Right and Left side). 

Figure 90: Noise contribution of each system at maximum noise level vehicle position. 

154 

 
 
 
 
 
Figure 91: Noise contribution of each system for LUrban of Sport TRAIL MANUAL vehicle. 

 
 
 
 
 
L3e-A3 vehicle: Sport NAKED 

Constant speed tests – 3rd gear 

Sport NAKED 

Figure 92: Baseline versus full mask noise test (Right and Left side). 

156 

 
 
 
 
 
 
 
Sport NAKED 

Figure 93: Noise contribution of each system over distance (Right and Left side). 

Figure 94: Noise contribution of each system at maximum noise level vehicle position. 

 
 
 
 
 
 
 
 
 
Acceleration tests – 3rd gear 

Sport NAKED 

Figure 95: Baseline versus full mask noise test (Right and Left side). 

158 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Sport NAKED 

Figure 96: Noise contribution of each system over distance (Right and Left side). 

Figure 97: Noise contribution of each system at maximum noise level vehicle position. 

 
 
 
 
 
 
Figure 98: Noise contribution of each system for LUrban of Sport NAKED vehicle. 

. 

160 

 
 
 
 
L3e-A3 vehicle: Sport TRAIL 

Constant speed tests – 4th gear 

Sport NAKED 

Figure 99: Baseline versus full mask noise test (Right and Left side) 

 
 
 
 
 
 
 
 
 
 
Sport TRAIL 

Figure 100: Noise contribution of each system over distance (Right and Left side) 

Figure 101: Noise contribution of each system at maximum noise level vehicle position 

162 

 
 
 
 
 
 
 
 
Acceleration tests – 4th gear 

Sport TRAIL 

Figure 102: Baseline versus full mask noise test (Right and Left side) 

 
 
 
 
 
 
 
Sport TRAIL 

Figure 103: Noise contribution of each system over distance (Right and Left side) 

Figure 104: Noise contribution of each system at maximum noise level vehicle position 

164 

 
 
 
 
 
Figure 105: Noise contribution of each system for LUrban of Sport TRAIL vehicle 

 
 
 
 
 
3.3.2. Vehicles tested according to the UN Regulation No. 09.08 

L5e-A vehicle: Unbodied Tricycle 

Acceleration tests – 2nd gear 

Unbodied tricycle 

Figure 106: Baseline versus full mask noise test (Right and Left side) 

166 

 
 
 
 
 
 
Unbodied tricycle 

Figure 107: Noise contribution of each system over distance (Right and Left side) 

Figure 108: Noise contribution of each system at maximum noise level vehicle position 

 
 
 
 
 
 
 
 
Figure 109: Noise contribution of each system for LUrban of Unbodied Tricycle vehicle 

168 

 
 
 
 
 
L5e-B vehicle: Bodied Tricycle 

Acceleration tests – 3rd gear 

Bodied tricycle 

Figure 110: Baseline versus full mask noise test (Right and Left side) 

 
 
 
 
 
 
 
 
Bodied tricycle 

Figure 111: Noise contribution of each system over distance (Right and Left side) 

Figure 112: Noise contribution of each system at maximum noise level vehicle position 

170 

 
 
 
 
 
 
Figure 113: Noise contribution of each system for LUrban of Bodied Tricycle vehicle 

3.4. Conclusions 

The analysis in the previous sections shows a global conclusion that can be generalised for all 
the vehicles studied herein. Table 25, below summarises the results of the NSR presented in 
the figures  above. We note  that for the measured  L-vehicle sub-categories,  the  main noise 
contributions in the value of LUrban are due to the exhaust system and the engine. This suggests 
that for these L-vehicles the most effective way  of reducing LUrban is by acting on these two 
vehicle components. This  is  shown  in  the  last  six  columns  of the  table that  show  the  brake 
down, in acoustic energy terms (expressed in %), of the Lurban values measured for the six L-
vehicle sub-categories as the sum of the contributions from the exhaust system, the engine, 
the transmission, the driveline, the intake and the tyres respectively. 

Figures  53  to  58  show  a  proposal  of  a  technical  feasibility  matrix,  for  each  vehicle  sub- 
category, for potential LUrban reductions based on the assumption of a combined reduction of 
the acoustic contribution of the exhaust system and the engine. Note that the Table 25 shows 
that  the  acoustic  contribution  of  these  vehicle  components  are  dominant  for  all  the  sub-
categories  studied.  The  colours  in  the  matrices  denote  areas  of  feasibility  based  on 
considerations about the technical difficulty and the design concepts associated to the noise 
reduction  of  the  considered  parts  (3,  6  and  9  dB(A)  reductions).  In  these  figures  we  have 
considered that Lurban reductions that can be achieved with exhaust system and engine noise 
contribution reductions up to 3B(A), respectively, are considered as ‘feasible’. This means that 
these  reductions  in  the  vehicle  components  can  be  achieved  through  an  evolutive  design 
process keeping the same basic technology concept in the vehicle parts. 

Noise  reductions  in  the  mentioned  components  around  6  dB(A)  would  have  a  ‘Limited 
feasibility’  in  the  sense  that  these  noise reductions  might  imply  technology  changes  whose 
cost or technical sophistication could prevent its practical materialisation. 

Noise reductions of the order of about 9 dB(A) are considered ‘unfeasible’ because, based on 
experience, in general this level of noise reduction in vehicle components normally involves 
disruptive technical changes in the corresponding component design concept. Therefore, the 
technological uncertainty associated with these levels of noise reductions tends to be very high 
in  both,  the  required  design  effort  and  the  potential  degree  of  achievement  and  ability  to 
implement. 

 
 
 
 
 
These matrices can be helpful if they are used in combination with the results from the CBA of 
Task 4. 

Table 25: Summary of the Noise Source Ranking for the various L-vehicle subcategories 
measured in this project. 

Lcrs (3rd) 

Lcrs (4th) 

Lwot (2nd) 

Lwot (3rd) 

Lwot (4th) 

Lurban 

UN-Reg. 

PMR 

Name in this report * 

Lex 
% 

Leng 
% 

Lt 
% 

Ld 
% 

Sport Naked 

58  36  0 

4 

Li 
% 

2 

R.41.04 

PMR > 50 

Sport TRAIL 

0 

22  63  0 

Sport TRAIL_Auto 

51  43  4 

2 

0 

0  48  47  0 

Sport TRAIL_Manual 

35  51  3 

1  10 

0  30  55  7 

0  15  0   
0   
0   

0 

5 

1 

7 

61  30 

0 

85 

86 

8 

8 

1 

0 

Lty* 
% 

Lex 
% 

Leng 
% 

Lt 
% 

Ld 
% 

Li 
% 

Lty* 
% 

Lex 
% 

Leng 
% 

Lt 
% 

Ld 
% 

Li 
% 

Lty* 
% 

Lex 
% 

Leng 
% 

Lt 
% 

PMR ≤ 50 

Bodied Tricycle 

R.09.08 

PMR > 50 

Unbodied Tricycle 

35  55  N/A  N/A  0  10   

34  57  N/A  N/A  5 

Ld 
% 

2 

1 

1 

Li 
% 

4 

1 

2 

Lty* 
% 

Lex 
% 

Leng 
% 

Lt 
% 

Ld 
% 

Li 
% 

Lty* 
% 

Lex 
% 

Leng 
% 

3 

4 

3 

4 

56  31 

31  28 

82  11 

86 

8 

1 

1 

0 

9  21  10  26  42 

0 

0 

0 

1 

6  62  20 

5  55  21 

38  53 

17  68 

Lt 
% 

0 

0 

0 

1 

0 

0 

Ld 
% 

3 

Li 
% 

2 

Lty* 
% 

8 

0  17  15 

0 

0 

0 

0 

0  19 

4  19 

4 

5 

2  12 

In Table 25, the meaning of the symbols at the head of the columns are*: 

  Lex: Acoustic energy contribution due to the exhaust system (%) 

  Leng: Acoustic energy contribution due to the engine (%) 

  Lt: Acoustic energy contribution due to the transmission (%) 

  Ld: Acoustic energy contribution due to the drive line (%) 

  Li: Acoustic energy contribution due to the intake (%) 

  Lty: Acoustic energy contribution due to the tyres (%) 

Figure 114: Technical feasibility for LUrban reduction for Sport TRAIL AUTO sub-category. 

Figure 115: Technical feasibility for LUrban reduction for Sport TRAIL MANUAL sub-category. 

172 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 116: Technical feasibility for LUrban reduction for Sport NAKED sub-category. 

Figure 117: Technical feasibility for LUrban reduction for Sport TRAIL sub-category. 

Figure 118: Technical feasibility for LUrban reduction for Unbodied Tricycle sub-category. 

Figure 119: Technical feasibility for LUrban reduction for Bodied Tricycle sub-category. 

The tables Figure 114: Technical feasibility for LUrban reduction for Sport TRAIL AUTO sub-category. - Figure 119: 
Technical feasibility for LUrban reduction for Bodied Tricycle sub-category. define a criterium to assess the feasibility 
associated to Lurban reductions in the range from 0 to 9 dB(A). These tables will be the base for 
providing  a guide to select  potential  noise limits  reductions for  L-vehicles considered  in the 
CBA in task 4. 

 
 
 
 
 
 
 
Figures 120 to 122 below show, as an example, the selected combination of the level of noise 
attenuation from the exhaust system and the engine that can produce (averaging for the four 
types of L3e-A3 vehicles) a Lurban reduction of 2 dB(A) (yellow cells) and 4 dB(A) (blue cells). 
Note that other attenuation values contained in other cells can also be taken as a reference 
for exhaust system and engine noise reduction for the same target reductions in Lurban. 

In this case, the values in the yellow and blue cells have been considered as possible reference 
cells close to the target of Lurban reduction of 2dB(A) and 4 dB(A) respectively. This allows us 
to assess the technical feasibility of such noise reductions, which has been taken into account 
in the CBA in task 4 and in the conclusions in task 5. 

Figure 120: The matrix used to define the level of noise attenuation from the exhaust sytem and the engine to produce 2dB(A) , 
(yellowcell ), and 4 dB(A) (blue cell ) in the Lurban of the unbodied tricycles sub-category. 

Figure 121: The four matrices used to define the level of noise attenuation from exhaust systems and the engine to produce on 
average 2dB(A), (yellow box), and 4 dB(A) (blue box) in the Lurban of the high performance L3e-A3 vehicles. Note that the values 
in the yellow and blue cells are averaged to end up with an average Lurban reduction for the sub-category under consideration. 

Figure 122: The matrix used to define the level of noise attenuation from the exhaust system and the engine to produce 2dB(A), 
(yellow cell), and 4 dB(A) (blue cell ) in the Lurban of the bodied tricycles sub-category (L5e-B) 

174 

 
 
 
 
 
 
 
 
 
4. Cost Benefit Analysis 

4.1. Introduction 

4.1.1. Objective 

The  objective  of  this  chapter  is  to  compare  different  options  for  noise  limits  of  L-  category 
vehicles1 through a cost-benefit analysis. 

4.1.2. Cost benefit analysis approach 

Cost-benefit  analysis  (CBA)  is  a  recommended  tool  in  any  decision-making  involving 
investment to achieve improvements at a societal scale. A CBA quantifies non- monetary or 
intangible aspects (like comfort or health), translating them into a monetary value (called social 
benefit)  and  contrasts  them  with  the  investments  to  be  made.  With  this  approach,  different 
policy scenarios can be compared to assess the welfare change attributable to it. The objective 
of a CBA is to facilitate a more efficient allocation of resources, demonstrating the convenience 
for society of a particular intervention as opposed to its alternatives [1]. 

For the approach to a CBA that measures the effects of reduction of noise this study takes the 
framework described in “Study on Euro 5 sound level limits of L-category vehicles” (TNO, 2017) 
[2]. 

The latter study is part of a series of previous studies in which different aspects of the reduction 
of noise levels produced by L-category vehicles were analysed. 

On  the  one  hand,  these  studies  describe  the  issue  of  excess  noise  produced  by  modified 
vehicles,  illegal  or  manipulated  exhausts  and  inappropriate  driving  behavior.  A  baseline 
scenario is assumed in which 25% of the motorcycle and moped fleet have excessive noise 
levels (Papadimitrou et al., 2016). They suggested that modified motorcycles exceed normal 
noise  levels  by  10-15  dB  and  mopeds  by  7-10  dB.  In  our  analysis,  we  have  included  the 
information  provided  but  adjusted  downwards  the  percentage  of  illegally  modified  vehicles, 
especially in an urban context. 

In line with the previous studies, and given the differences in the use of L-category vehicles in 
Northern  and  Southern  Europe,  we  have  carried  out  the  analysis  separately  for  these  two 
regions. In addition, for Northern countries a parameter of exposure time to noise is introduced 
since the use of these vehicles, especially the loudest ones such as touring motorcycles, is 
mostly limited to weekends. This is primarily due to weather conditions which in countries such 
as  Greece,  Spain,  Portugal  or  Italy  allowing  an  almost  daily  use,  while  it  is  limited  to  the 
summer months in countries further north (TASK 1.2: Vehicle use intensity). 

In addition, we have carried out the analysis separately for urban and rural areas, given the 
substantial differences in exposure from noise emitted by motorcycles. 

Once  the  procedure  carried  out  in  the  2017  study  had  been  analysed,  based  on  the 
conclusions of the stakeholder questionnaire, some of the hypotheses have been updated. In 
addition, some of the reference unit costs have been updated with more recent data and data 
analysed in the present study. 

1 Mopeds and motorbikes, as well as all-terrain vehicles (quads) and other small vehicles with 3 or 4 wheels 

176 

 
 
 
                                                 
4.2. CBA Model 

4.2.1. Scope 

The scope of this CBA is the comparative analysis of different policy scenarios comprising new 
limits in the regulation of permitted noise levels for new L-category vehicles and enforcement 
measures of those vehicles that are illegally modified (mostly the exhaust system) and as a 
result exceed the permitted noise levels. 

The appraisal period, starting with new limits potentially taking effect, is 15 years. The effects 
of the new sound levels regulation will take more than a decade to have full effect due to the 
timings of entry into force of noise limit changes and average vehicle replacement rates. 

The geographical scope comprises the EU27 Member States. In addition, two regions, North 
and South, have been differentiated due to the greater presence of mopeds and motorcycles 
in the Mediterranean countries (Southern Europe). 

In addition, we have carried out the analysis separately for urban and rural areas, given the 
substantial  differences  in  exposure  especially  from  noise  emitted  by  motorcycles  and 
differences in the impact of reducing noise emissions of L-category vehicles in an area with 
more or less background noise. 

4.2.1. Noise level reduction 

Noise level data sources 

The CBA is based on comparing different scenarios for the regulation of noise levels emitted 
by L-category vehicles with the status quo, represented by a base scenario. Benefits in each 
scenario are generated through a reduced exposure of population to noise levels compared to 
the base scenario. Exposure of population is estimated by noise levels at building facades and 
the respective number of affected residents. To estimate noise exposure at building facades, 
two different methodologies have been used for urban and rural environments to account for 
the differences these two contexts comprise in terms of noise perception. 

Urban areas tend to be characterised by constant levels of traffic noise that dilute noise emitted 
by L-category vehicles. For these areas, we have used outputs from the CNOSSOS-EU [3] 
model to estimate overall traffic noise levels and the impact of changes in noise emitted by L-
category vehicles on these. The methodology is described in more detail in following section 
on noise level reduction. 

In rural  areas,  noise  emission  events  of  singular  nature  play  a much  larger  role  in  creating 
annoyance.  Therefore,  we  have  calculated  noise  reduction  levels  using  a  different 
methodology to better adjust to the logarithmic nature of sound measurement in accordance 
with ISO 1996-1. The methodology is described in more detail in second following section on 
noise levels in rural environment. 

 
 
 
 
 
 
 
 
 
Noise levels in urban environment 

For urban roads, the total traffic noise level at facades is denominated ΔLDEN2. The noise level 
reduction ΔLDEN in each scenario is consequently based on the difference between LDEN in a 
specific policy scenario and LDEN in the base scenario. 

The  relationship  between  a  specific  noise  emission  limit  for  L-category  vehicles  and  its 
corresponding LDEN has been adopted from model outputs of CNOSSOS-EU [3] presented in 
TNO (2017) [2]. 

In this model, the LDEN values in Northern European Member States have been calculated by 
including light vehicle, heavy vehicle, motorcycle and moped traffic on main roads and light 
vehicle and moped traffic on residential roads which are based on Eurostat figures3. 

In  Southern  Member  States  all  types  of  vehicles  (including  motorcycles  and  mopeds)  are 
considered when calculating noise levels on main and residential roads. To calculate the LDEN 
value, a lower impact of heavy vehicles that only affects 50% of the road network and a higher 
proportion of L-category vehicles than in Northern countries are assumed. 

To obtain average noise levels in urban areas, noise levels at residential and main roads are 
weighted  by  their  respective  total  length.  The  table  below  shows  resulting  LDEN  values 
separately by road type and geographical region. 

Table 26: Façade noise level ∆LDEN (dB) by road type and region. TNO (2017) [2]. 

Northern Europe 

Southern Europe 

Residential roads 

Main roads 

Residential roads 

Main roads 

52.55 

63.36 

59.42 

68.88 

Average: 53,97 

Average: 58,77 

The difference between the reference noise level and the resulting noise levels in the different 
scenarios analysed in TNO 2017 [2] is defined as ΔLDEN (noise level reduction). Table 27 shows 
the resulting differences in noise levels ΔLDEN for noise limit reductions of 2 dB and 5 dB, and 
for both limit reductions a scenario with no change in the percentage of illegally modified L-
category vehicles (25% IL) and another with a reduction of this percentage to 0% (0% IL). 

Table 27: Expected typical LDEN noise level reduction at the façade in Northern and 
Southern European urban areas (L-cat) (TNO 2017 [2]). 

Scenario 

Base scenario, 2020, 0 dB, 25% IL 

ΔLDEN (dB) 

Northern EU 
Urban 

Southern EU 
Urban 

2040, 2 dB, 25% IL 

2040, 5 dB, 25% IL 

2040, 2 dB, 0% IL 

2040, 5 dB, 0% IL 

0.31 

0.53 

0.35 

0.71 

0.54 

1.46 

0.97 

1.95 

2 Day-evening-night level. It is a descriptor of noise level based on energy equivalent noise level (Leq) over a whole day with a 
penalty of 10 dB(A) for night time noise (23.00-7.00) and an additional penalty of 5 dB(A) for evening noise (i.e. 19.00-23.00). 

3 Eurostat (2021) Road traffic on national territory  by  type of  vehicle and  type of  road  (million Vkm) (road_tf_road) 

178 

 
 
 
 
 
 
 
 
                                                 
The present study takes these values and adjusts them for a new assumption: a 12.5% share 
of  illegally  modified  L-category  vehicles  in  urban  areas  is  assumed  for  the  base  scenario, 
compared  to  25%  in  TNO  2017  [2].  This  is  to  account  for  the  differences  in  circumstances 
between  urban  and  rural  areas  regarding  this  matter,  specifically  due  to  urban  areas 
accounting  for  a  larger  share  of  public  and  commercial  fleet  vehicles,  including  those  with 
electric propulsion. In addition, it is understood that residents in urban areas are more likely to 
use L-category vehicles as practical means to adjust to dense urban traffic, rather than owning 
the vehicle for leisure motorcycle tours. 

The resulting and final values for differences in noise levels ΔLDEN used to estimate benefits in 
the different tested scenarios in the present study are shown in Table 28. 

Table 28: Values for ∆LDEN noise level reduction at the façade in Northern and Southern EU 
Member States at urban areas used by the present study. 

Scenario 

Base scenario, 0 dB, 12,5% urban IL 

Future, 2 dB, 12,5% urban IL 

Future, 4 dB, 12,5% urban IL 

Future, 2 dB, 0% IL 

Future, 4 dB, 0% IL 

ΔLDEN (dB) 

Northen EU 
Urban 
0 

Sourthern EU 
Urban 
0 

0.26 

0.47 

0.28 

0.51 

0.45 

1.05 

0.67 

1.28 

Noise levels in rural environment 

To  calculate  the  LDEN  values  in  rural  environments,  a  methodology  to  better  reflect  the 
occurrence of single noise events is used. This methodology reflects better the effects of noise 
impact in rural areas, where noise impacts are more due to specific peaks that stand out from 
the  usually  low  levels  of  background  traffic  noise.  To  estimate  these  peaks,  a  logarithmic 
calculation is used according to ISO 1996-1. This method allows a better approximation to the 
experienced noise levels compared to environments with constant high levels of traffic noise 
such as in urban areas. 

For this calculation, a percentage of illegal vehicles of 25% has been assumed which is in line 
with TNO (2017) [2]. 

The resulting values for ΔLDEN in rural areas are shown in Table 29. 

Table 29: Values for ∆LDEN noise level reduction at the façade in Northern and Southern EU 
in rural areas used by the present study 

Different scenarios 

Present, 0 dB, 25% rural IL, REF 

Future, 2 dB, 25% rural IL 

Future, 4 dB, 25% rural IL 

Future, 2 dB, 0% rural IL 

Future, 4 dB, 0% rural IL 

ΔLDEN (dB) 

Northern EU 
Rural 
0 

Southern EU 
Rural 
0 

0.06 

0.11 

2.22 

2.32 

0.12 

0.20 

5.54 

5.95 

 
 
 
 
 
 
 
 
4.2.2. Socio-economic benefits 

Socio-economic  benefits  are  based  on  reductions  in  traffic  noise  levels  ΔLDEN.  The  specific 
benefits considered in this study are related to health and amenity. The methodologies used 
for each are described in more detail in the following sections. 

Noise level exposure assumptions 

The  population  living  along  the  considered  road  network  is  not  continually  exposed  to 
excessive noise levels. E.g. during the day in urban areas, and especially during longer time 
periods in rural areas, residents are either not affected by noise from traffic or do not perceive 
it as generating the same levels of annoyance as for instance during night time. For this reason, 
we have applied noise exposure factors for time of the week to account for differences between 
weekday and weekend behaviour, and for time of day to account for differences between day 
and night time behaviour.  

In this respect, we have assumed a lower exposure of Northern European Member States due 
to their specific usage trends of L-category vehicles. The weather conditions in these areas do 
not allow continuous use of the motorcycles during the year but only during around 20% of the 
time. 

In rural  areas,  the motorcycle  traffic relevant for emission  of  excessive noise levels  in rural 
areas is limited to touristic routes on specific roads and especially on weekends. A factor of 
8% has therefore been applied to rural areas. 

The  second  assumption  for  the  Southern  European  Member  States  is  a  higher  use  of  L-
category  vehicles  throughout  the  year.  However,  despite  weather  conditions  being  more 
favorable to motorcycle driving, the effects of reducing noise levels in L- category vehicles are 
not  perceived  on  all  roads.  The  study  considers  a  factor  of  30%  for  exposure  level  of  the 
population of urban areas and an 8% for rural areas. below summarises exposure factors for 
the different considered segments. 

Table 30: Exposure factors used to calculate health and amenity benefits 

Northern EU 

Southern EU 

Urban 

Rural 

20% 

8% 

30% 

8% 

Health benefits 

The prolonged exposure to noise results in a number of health endpoints like ischaemic heart 
disease,  stroke,  dementia,  hypertension,  effects  on  sleep  and  annoyance  [4].  These  health 
conditions come with a cost for society which can be  quantified using health unit costs, i.e. 
marginal costs related to health conditions per unit of the generating factor (e.g. 1dB of noise 
increase). In this analysis, following a review of different sources including the “Handbook on 
the external cost of transport 2019”, cost values are based on Defra (2014) [5]. The following 
table shows health costs (VH) per changes of noise levels of 1 dB and how this marginal cost 
varies depending on the current noise level. 

Table 31: Health costs (€2016/person/dB/year) based on Defra (2014) for a change of 1 dB 
for different levels of LDEN 

The annual benefit for health improvement due to reduction of noise is calculated from: 

180 

 
 
 
 
 
𝐵ℎe𝑎𝑙𝑡ℎ =  𝑉𝐻 · 𝑃 · 𝑁𝑅 · 𝐸, 

where: 

VH = health benefit per person per dB noise reduction [€/dB]  

P = population exposed 

NR = dB noise reduction of the average equivalent noise level [dB]  

E = exposure factor 

Amenity benefits 

Benefits resulting from a reduction in annoyance from extensive traffic noise is here  defined 
as amenity benefits. The results of a comprehensive and recent study suggests that the cost 
of annoyance is increasing strongly with increasing noise levels (Bristow, et al., 2015) [5], as 
shown in the following table. 

Table 31: Annoyance costs used for EU28 (€2016/person/dB) based on (Bristow, et al., 2015) 

The annual benefit for amenity improvement due to reduction of noise is calculated from: 

𝐵Æ = 𝑉Æ · 𝑃 · 𝑁𝑅 · 𝐸 

VA = amenity benefit per person per dB noise reduction [€/dB]  

P = population exposed 

NR = dB noise reduction of the average equivalent noise level [dB]  

E = exposure factor 

Resulting values of socio-economic benefits 

The cost  of  health conditions  and  annoyance  has  been  determined individually  for  different 
road categories in both, northern and southern EU Member States to account for the specific 
differences  in  current  noise  levels  LDEN  in  each  of  these  segments.  The  road  categories 
considered are residential and main roads (for urban environment), and rural roads (for rural 
environment). The table below shows the unit prices for each road and cost category used in 
this analysis. To compare cost values with those used by TNO 2017 [2], the table also shows 
an average cost for health and annoyance for the whole of the EU weighted by population in 
each segment. While average health cost is only around 60% of that used in TNO 2017 [2], 
annoyance costs are more than double, resulting in a total unit cost which is around 50% higher 
than that used in TNO 2017 [2]. 

 
 
 
 
 
 
 
 
Table 33: Unit benefit prices used in the CBA 

Northern Europe 

Southern Europe 

Residential 
roads 

Main 
roads 

Rural 
roads 

Residential 
roads 

Main 
roads 

Rural 
roads 

Average 
(€2016/person/d 
B) 

TNO (2017) [2] 
(€2016/person/d 
B) 

LDEN at façade 
(dB) 

52.5 

63.4 

60.7 

59.4 

68.9 

65.6 

Annoyance 

14.00 € 

28.00 € 

28.00 € 

28.00 € 

54.00 € 

54.00 € 

25.35 € 

12.21 € 

Health 

3.00 € 

6.00 € 

6.00 € 

3.00 € 

9.00 € 

9.00 € 

4.34 € 

7.26 € 

Exposed people 

27,605,425 

10,295,72 
8 

2,985,761  16,919,454  6,310,285 1,829,982 

TOTAL 

TOTAL 

29.69 € 

19.47 € 

4.2.3. Socio-economic cost 

The cost necessary to achieve the above described benefits is based on two elements. On the 
one  hand,  increased  cost  for  industry  due  to  required  additional  efforts  in  research  and 
development  (R&D)  and  manufacturing  and  on  the  other  hand,  the  cost  of  authorities, 
especially related to an increased level of enforcement. 

Industry cost 

Industry costs are associated with the production of new L-category vehicles that must comply 
with the new limits for permitted noise emissions. These costs derive from the cost of R&D and 
the cost of manufacturing (manufacturing plus tooling costs) of more silent components (such 
as exhaust pipes and engines) and its integration in the vehicle. 

The cost values have been obtained from a stakeholder consultation carried out as part of this 
study  and  from  costs  presented  by  TNO  in  2017  [2],  which  are  based  on  stakeholder 
consultation as well. The table below shows cost details per manufactured L-category vehicle 
unit, provided by different vehicle manufacturers and those presented by TNO. It further shows 
average values for each cost category which have been used in the analysis. 

Table 34: Proposed R&D and manufacturing costs 

Authority cost 

The other aspect of the CBA's scope is the analysis of the effects that varying enforcement 
efforts will have on vehicles that do not comply with the established noise limits. These efforts 
have a cost. 

182 

 
 
 
 
 
 
 
 
 
To achieve full compliance with current noise limits, it has been assumed that it is necessary 
to incorporate an additional surveillance patrol for every million inhabitants. The daily cost of 
the patrol has been calculated using these values: 

Table 35: Daily cost of one control patrol, TNO (2017)  

For the analysis it has been assumed that controls are carried out during a fifth of the year (73 
days).  With  a  total  of  447.3  million  inhabitants  in  the  EU27,  the  cost  associated  with  the 
authorities  will  be  44.3M€.  This  cost  is  only  considered  in  those  scenarios  that  explicitly 
envisage  a  reduction  of  illegal  vehicles  to  0%.  Looking  forward,  new  technology  might 
substantially  reduce  these  costs  in  the  future,  for  example  by  means  of  automated 
camera/noise monitoring systems. 

4.2.4. Discount rate and Net Present Value 

To  compare  the  different  proposed  scenarios,  the  Net  Present  Value  (NPV)  and  the 
Benefit/Cost ratio are used. 

The NPV represents the benefits minus the costs, which both are brought to reference year 
terms using a discount rate. The NPV is given by the following formula: 

with Bi = benefits in year i, Ci = costs in year i, and r = discount rate. 

The  benefit  to  cost  ratio  (BCR)  is  calculated  over  the  whole  appraisal  period  considering  a 
discount  rate  of  4%,  as  suggested  in  EU  guidelines  (EC,  2015).  This  ratio  is  applied  to 
determine  the  present  value  of  future  costs  or  benefits.  These  values  show  the  social 
preference rate, defined as the value of the future cost or benefits in today´s terms. 

In  addition,  both  unit  costs  and  benefits  are  assumed  to  increase  by  an average  of  1%  per 
year, representing price increases due to inflation. 

4.3. Scenarios 

The study carried out stakeholder consultation, with government agencies and manufacturers, 
and the scenarios have been defined based on their views on technical and economic viability, 
strategic policy objectives and based on outcomes of earlier tasks of this study. 

Four  scenarios  have  been  evaluated  based  on  different  hypothesis  of  reduction  of  noise 
emission limits for L-category vehicles. The four chosen levels of noise limit reduction are as 
follows: 

  0 dB – Increased enforcement only 

  2 dB – Moderate reduction 

  4 dB – Ambitious reduction 

 
 
 
 
 
  2dB+2dB – Stepwise reduction (with two implementation dates) 

4.3.1. Common assumptions 

Time period 

The time horizon of the analysis is 15 years, from 2021 to 2036. For each scenario there are 
three key dates: 

The first date is the official announcement of the policy in year 1. The announcement of the 
new policy will be the start of some costs like R&D and some substitution of vehicles will start 
to take place. 

The second key date is the entry into force, from which on all new type approvals must comply 
with the new limits (2 years after announcement, 4 years for 4dB scenario). 

The third key date is the end of the transition period, from which on all new sold vehicles must 
comply with the new limits (usually 2-3 years after entry into force). 

Population and L-category vehicle market growth 

All  scenarios  present  the  same  assumptions  of  population  growth  and  L-category  vehicle 
market size growth of 1% p.a., which is in line with TNO (2017) [2]. 

Analysis of illegal vehicles 

Each scenario presents three variants or sub-scenarios in which different levels of enforcement 
efforts are analysed: 

  Variant 1: with 0% of illegally modified vehicles and highest enforcement cost; 

  Variant 2: with 5% of remaining illegally modified vehicles and moderate enforcement 

cost; and 

  Variant  3:  with  12.5%  and  25%  of  illegally  modified  vehicles  (urban  and  rural 

respectively) without additional enforcement cost (current level). 

This  has  implications  on  the  cost  of  enforcement  and  on  the  reduction  of  emitted  noise.  A 
variant  with  5%  illegally  modified  vehicles  has  been  included  to  analyse  a  more  realistic 
scenario, in which enforcement efforts do not reach all territories to the same extent, but the 
costs are nearly the same. 

4.3.2. Definition of scenarios 

Scenario A - Only enforcement 

Scenario A is an enforcement-only scenario in which no reduction of current noise emission 
limits is envisaged. 

Assumptions: 

  Noise reduction is exclusively due to the increased intensity of controls (enforcement 
efforts),  both  roadside  and  as  part  of  Periodic  Technical  Inspections  (PTIs).  Noise 
reduction  is  achieved  through  increased  (or  full  in  case  of  0%  remaining  illegally 
modified vehicles – 0% IL) compliance with existing noise emission limits for L-category 
vehicles. 

  The time to reach the respective remaining percentage of illegally modified vehicles in 
each sub-scenario is 10 years. Increased effort in enforcement takes place from year 
1 (mid 2021). 

184 

 
 
The following table shows the benefits and costs for all three variants of scenario A, and the 
respective benefit-cost (B/C) ratios, net present value (NPV) and first year with a positive NPV 
(FPY).  The  third  variant  with  no  additional  enforcement  efforts  (%IL  –  25%)  represents  the 
base case (or do-nothing scenario) but is included for consistency across all scenarios. 

Table 36: Results of Scenario A and its sub-scenarios 

Urban 

Rural 

North 

South 

North 

South 

Scenario  %IL 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Costs 
(M€) 

B/C ratio 

NPV 
(M€) 

FPY 

A 
A 
A 

0% 
5% 
25% 

0.07 
0.04 
0.00 

73 
44 
0 

0.30 
0.18 
0.00 

785 
471 
0 

2.07 
1.75 
0.00 

121 
103 
0 

4.97 
3.94 
0.00 

235 
191 
0 

474 
465 
0 

2.6 
1.7 
n.a. 

741  2027 
344  2029 

0 

- 

The following chart shows the evolution of each individual benefit and cost element over the 
evaluation horizon. 

Figure 123: Annual benefits for amenity and health and costs for R&D, production and enforcement, and totals, for Scenario A 
(sub scenario of 5% illegal exhausts) in M€. 

Scenario B - Moderate (-2 dB) 

Assumptions: 

  2 dB limit reduction for L-category vehicles. 

  The  policy  announcement  is  in  year  1  (mid  2021),  entry  into  force  for  new  type 
approvals in year 3 (mid 2024) and 2 years transition period for compliance of all new 
vehicles. 

  The natural substitution of all existing L-category vehicles is assumed to take 10 years 
from the start of the policy, after which all L-category vehicle models on the road are 
compliant  with  the  new  limit.  However,  this  does  not  apply  to  illegally  modified  L-
category vehicles. 

 

In  addition  to  noise  limit  reduction,  further  noise  reduction  is  achieved  through 
increased  (or  full  in  case  of  0%  remaining  illegally  modified  vehicles  –  0%  IL) 
compliance with existing and new noise emission limits for L-category vehicles. In turn, 
this will be achieved through increased intensity of controls (enforcement efforts), both 
roadside and as part of Periodic Technical Inspections (PTIs). 

 
 
 
 
 
 
 
 
 
  The time to reach the respective remaining percentage of illegally modified vehicles in 
each sub-scenario is 10 years. Increased effort in enforcement takes place from year 
1. 

A 2dB reduction of noise emission limits of L-category vehicles leads to accumulated benefits 
outweighing  accumulated  cost  by  a  ratio  between  1.4  and  1.2,  depending  on  the  level  of 
enforcement. 

The following table shows the benefits and costs for all three variants of scenario B, and the 
respective B/C ratios, net present value (NPV) and first year with a positive NPV (FPY). 

Table 37: Results of Scenario B and its sub-scenarios 

Urban 

Rural 

North 

South 

North 

South 

Scenario  %IL 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Costs 
(M€) 

B/C ratio 

NPV 
(M€) 

FPY 

B 
B 
B 

0% 
5% 
25% 

0.28 
0.28 
0.26 

260 
252 
241 

0.67 
0.58 
0.46 

1,471 
1,282 
999 

2.22 
1.88 
0.07 

92 
78 
3 

5.54 
4.36 
0.12 

219 
176 
9 

1,446 
1,438 
1,052 

1.4 
1.2 
1.2 

595  2032 
350  2034 
200  2034 

The following figure shows the evolution of each individual benefit and cost element over the 
evaluation horizon. 

Figure 124: Annual benefits for amenity and health and costs for R&D, production and enforcement, and totals, for Scenario  B 
(sub scenario of 5% illegal exhausts) in M€. 

Scenario C - Ambitious (-4 dB) 

Assumptions: 

  4 dB limit reduction for L-category vehicles. 

  The announcement of the policy is in year 1 (mid 2021), entry into force for new type 
approvals in year 5 (mid 2026) and 2 years transition period for compliance of all new 
vehicles. 

  The natural substitution of all existing L-category vehicles is assumed to take 15 years 
from the start of the policy, after which all L-category vehicle models on the road are 
compliant  with  the  new  limit.  However,  this  does  not  apply  to  illegally  modified  L-
category vehicles. 

 

In  addition  to  noise  limit  reduction,  further  noise  reduction  is  achieved  through 
increased  (or  full  in  case  of  0%  remaining  illegally  modified  vehicles  –  0%  IL) 

186 

 
 
 
 
 
 
 
 
compliance with existing and new noise emission limits for L-category vehicles. In turn, 
this will be achieved through increased intensity of controls (enforcement efforts), both 
roadside and as part of Periodic Technical Inspections (PTIs). 

  The time to reach the respective remaining percentage of illegally modified vehicles in 
each sub-scenario is 10 years. Increased effort in enforcement takes place from year 
1. 

Due to the higher noise level limits (4dB), the policy enters into force later than in Scenario A 
to give industry more time to develop and bring to market compliant vehicles. 

The following table shows the benefits and costs for all three variants of scenario C, and the 
respective B/C ratios, net present value (NPV) and first year with a positive NPV (FPY). 

Table 38: Results of Scenario C and its sub-scenarios 

Urban 

Rural 

North 

South 

North 

South 

Scenario  %IL 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Costs 
(M€) 

B/C ratio 

NPV 
(M€) 

FPY 

C 
C 
C 

0% 
5% 
25% 

0.52 
0.50 
0.47 

358 
344 
324 

1.27 
1.18 
1.05 

2,092 
1,951 
1,739 

2.32 
1.97 
0.11 

70 
60 
4 

5.95 
4.65 
0.20 

217 
173 
13 

3,001 
2,995 
2,682 

0.9 
0.8 
0.8 

-264  2038 
-466  2039 
-602  2040 

This scenario has the largest costs which have to be assumed in the first years of the analysis 
period. There are also substantial benefits produced by this scenario but the maximum annual 
benefit is achieved only in year 15 (2035). The benefit/cost ratio is negative because of the 
longer implementation period, and as such discounted benefits do not exceed accumulated 
costs in today´s terms.  

The following chart shows the evolution of each individual benefit and cost element over the 
evaluation horizon. 

Figure 125: Annual benefits for amenity and health and costs for R&D, production and enforcement, and totals, for Scenario  C 
(sub scenario of 5% illegal exhausts) in M€. 

Scenario D - Stepwise (-2 dB and -2 dB) 

In  this  scenario,  a  2dB  reduction  enters  into  force  in  year  3,  followed  by  an  additional  2dB 
reduction after two more years. 

 
 
 
 
 
 
 
 
 
 
Assumptions: 

  4dB limit reduction for L-category vehicles with a stepwise implementation of 2dB each 

  The announcement of the policy is in year 1 (mid 2021), entry into force at year 3 (mid 
2024)  for  2dB  reduction  for  new  type  approvals  and  2  years  transition  period  for 
compliance  of  all  new  vehicles  in  2026.  Also,  in  2026  entry  into  force  of  additional 
reduction of 2dB, and 2 years transition period for compliance of all new vehicles in 
2028. 

  The natural substitution of all existing L-category vehicles is assumed to take 15 years 
from the start of the policy, after which all L-category vehicle models on the road are 
compliant  with  the  new  limit.  However,  this  does  not  apply  to  illegally  modified  L-
category vehicles. 

 

In  addition  to  noise  limit  reduction,  further  noise  reduction  is  achieved  through 
increased  (or  full  in  case  of  0%  remaining  illegally  modified  vehicles  –  0%  IL) 
compliance with existing and new noise emission limits for L-category vehicles. In turn, 
this will be achieved through increased intensity of controls (enforcement efforts), both 
roadside and as part of Periodic Technical Inspections (PTIs). 

  The time to reach the respective remaining percentage of illegally modified vehicles in 
each sub-scenario is 10 years. Increased effort in enforcement takes place from year 
1. 

The following table shows the benefits and costs for all three variants of scenario D, and the 
respective B/C ratios, net present value (NPV) and first year with a positive NPV (FPY). 

Table 39: Results of Scenario D and its sub-scenarios 

Urban 

Rural 

North 

South 

North 

South 

Scenario  %IL 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Costs 
(M€) 

B/C ratio 

NPV 
(M€) 

FPY 

D 
D 
D 

0% 
5% 
25% 

0.52 
0.50 
0.47 

481 
464 
438 

1.27 
1.18 
1.05 

2,795 
2,570 
2,228 

2.32 
1.97 
0.11 

107 
91 
5 

5.95 
4.65 
0.20 

326 
255 
18 

2,717 
2,709 
2,265 

1.4 
1.2 
1.2 

991  2032 
671  2033 
424  2034 

The following chart  shows the evolution of each individual benefit and cost element over the 
evaluation horizon 

188 

 
 
 
 
 
 
 
 
Figure 126: Annual benefits for amenity and health and costs for R&D, production and enforcement, and totals, for Scenario  D 
(sub scenario of 5% illegal exhausts) in M€. 

In this scenario, the first 2dB reduction is implemented within the same timeframe as Scenario 
B, so that some of the benefits are achieved quickly. The second step helps to achieve greater 
benefits, reaching a maximum benefit of 400 M€/year in 2032. 

4.4. Discussion of results 

The results of each scenario and their variants are shown separately for rural and urban areas 
and for Northern and Southern EU Member States in the table below. The total benefit of urban 
areas  is  higher  than  those  of  rural  areas  because  the  exposure  to  noise  and  exposed 
population are larger. In addition, benefits generated in the Southern EU Member States are 
higher because of the larger number of L- category vehicles and the larger exposure levels. 

Table 40: Results of Scenario D and its sub-scenarios 

Urban 

Rural 

North 

South 

North 

South 

Scenario  %IL 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Lden 
(dB) 

Benefits 
(M€) 

Costs 
(M€) 

B/C ratio 

NPV 
(M€) 

FPY 

A 
A 
A 
B 
B 
B 
C 
C 
C 
D 
D 
D 

0% 
5% 
25% 
0% 
5% 
25% 
0% 
5% 
25% 
0% 
5% 
25% 

0.07 
0.04 
0.00 
0.28 
0.28 
0.26 
0.52 
0.50 
0.47 
0.52 
0.50 
0.47 

73 
44 
0 
260 
252 
241 
358 
344 
324 
481 
464 
438 

0.30 
0.18 
0.00 
0.67 
0.58 
0.46 
1.27 
1.18 
1.05 
1.27 
1.18 
1.05 

785 
471 
0 
1,471 
1,282 
999 
2,092 
1,951 
1,739 
2,795 
2,570 
2,228 

2.07 
1.75 
0.00 
2.22 
1.88 
0.07 
2.32 
1.97 
0.11 
2.32 
1.97 
0.11 

121 
103 
0 
92 
78 
3 
70 
60 
4 
107 
91 
5 

4.97 
3.94 
0.00 
5.54 
4.36 
0.12 
5.95 
4.65 
0.20 
5.95 
4.65 
0.20 

235 
191 
0 
219 
176 
9 
217 
173 
13 
326 
255 
18 

474 
465 
0 
1,446 
1,438 
1,052 
3,001 
2,995 
2,682 
2,717 
2,709 
2,265 

2.6 
1.7 
n.a. 
1.4 
1.2 
1.2 
0.9 
0.8 
0.8 
1.4 
1.2 
1.2 

741  2027 
344  2029 

0 

- 

595     2032 
350     2034 
200     2034 
-264  2038 
-466  2039 
-602  2040 
991     2032 
671     2033 
424     2034 

The following figure shows a comparison of total benefits and costs and resulting B/C ratio for 
each scenario. The highest B/C ratio can be achieved in scenario A (2.6 and 1.7, for 0% and 
5% of remaining illegally modified vehicles, respectively). However, total benefits in Scenario 
A  only  reach  up  to  1,200M€.  This  is  the  lowest  amount  of  total  benefits  across  all  tested 
scenarios.  In  comparison,  scenarios  B  and  D  have  a  lower  B/C  ratio  of  1.4  but  generate 

 
 
 
 
 
 
 
 
 
 
 
 
benefits  of  around  2,000M€  and  3,700M€,  respectively  for  the  0%  of  remaining  illegally 
modified vehicles variant. 

For all scenarios, the costs are higher than the benefits in the first years, as investments are 
made up front, but also because the effective reductions in LDEN are only marginal in first years 
and reach full effect after most of the vehicles are replaced. 

Figure 127: Comparison of total benefits and costs and resulting B/C ratio for each scenario 

4.4.1. Differences between scenarios 

The results of the scenarios show that the best benefit-cost relation occurs when there are only 
enforcement  policies  and  no  industry  cost  (scenario  A  –  only  enforcement).  The  benefits, 
mainly in the southern EU Member States, compensate authority costs in only a few years. 
However, it is the scenario that produces least benefits mostly because impact in the urban 
areas, where a majority of exposed population lives, is limited. 

On the other hand, the highest net present value (NPV) occurs in the two-step implementation 
option (scenario D stepwise - 2dB+2dB). The manufacturing costs are more evenly distributed 
than in scenario C (4dB reduction implemented in one step), by reducing the initial investment. 

The following charts show a comparison of annual total benefits, annual total costs, and net 
present value (NPV) for each scenario and its respective variants. 

Scenarios  C  and  D  are  the  ones  that  present  both  the  highest  benefits,  thanks  to  a  larger 
reduction in noise limits (4dB), but also highest costs since they require a greater investment 
by industry. 

190 

 
 
 
 
 
Figure 128: Annual benefits for each scenario in M€ 

Figure 129: Annual cost for each scenario in M€ 

Scenarios D and A, followed by B and C in their respective variants with 0% of illegally modified 
vehicles (0%) are the ones that present the highest NPVs. 

 
 
 
 
 
 
 
Figure 130: Annual cost for each scenario in M€ 

4.4.1. Comparison of results with earlier work 

In  this  section,  the  results  of  equivalent  or  comparable  scenarios  in  terms  of  noise  limit 
reduction  and  enforcement  between  TNO  2017  [2]  and  the  present  study  are  compared. 
However,  the  comparability  of  these  scenarios  is  limited  due  to  differences  in  underlying 
assumptions.  E.g.  the  analysis  time  horizon  varies  between  TNO  2017  [2]  and  the  present 
study by 5 years (20 years and 15 years, respectively), but also changes in unit costs for health 
and annoyance and industry costs. 

The tables below first show results of TNO 2017 [2], including noise limit reduction (Lcat Lim), 
remaining percentage of illegally modified vehicles (%IL), benefits by Northern and Southern 
EU Member States (Benefits North and Benefits South, respectively), as well as total benefits, 
costs  and  the  resulting  benefit-cost  ratio  (B/C  Ratio).  The  second  table  shows  the 
corresponding results for the present study. 

Table 41: Differences between equivalent scenarios TNO 2017 [2] – Present Study Mixed 
Model 

TNO 2017 [2] (20 year analysis horizon) 

Scenario 

Lcat Lim 

%IL  Benefits North (M€)  Benefits South (M€)  Total Benefits (M€) 

Total Costs (M€) 

B/C Ratio 

B – 0% 

-2 dB 

0% 

B – 25% 

-2 dB 

25% 

≈ C – 0% 

-5 dB 

0% 

≈ C – 25% 

-5 dB 

25% 

97 

66 

186 

125 

1,107 

601 

2,227 

1,661 

1,204 

668 

2,412 

1,787 

631 

306 

1,286 

962 

1.9 

2.2 

1.9 

1.9 

Present study (15 year analysis horizon) 

Scenario 

Lcat Lim 

%IL  Benefits North (M€)  Benefits South (M€)  Total Benefits (M€) 

Total Costs (M€) 

B/C Ratio 

B – 0% 

-2 dB 

0% 

B – 25% 

-2 dB 

25% 

C – 0% 

-4 dB 

0% 

C – 25% 

-4 dB 

25% 

351 

244 

428 

328 

1,689 

1,007 

2,309 

1,751 

2,040 

1,251 

2,737 

2,079 

1,445 

1,052 

3,001 

2,682 

1.4 

1.2 

0.9 

0.8 

The  total  benefits  are  greater  in  the  present  study.  For  the  Northern  EU  Member  States, 
benefits are around three times higher, while for the southern EU Member States benefits are 

192 

 
 
 
of  the  order  of  1.5  times  higher,  compared  to  the  2017  study.  This  is  directly  related  to 
differences in the health and annoyance unit costs used for the analysis. Total costs are also 
2 or 3 times higher in the present study mainly due to industry related costs. 

The B/C ratios are smaller in the current study than in TNO (2017) [2]. The reduction of the 
analysis  period  leads  to  a  reduction  in  total  benefits.  This  is  because  benefits  compensate 
initial costs especially in the last years of the analysis. Five more years of analysis period used 
by TNO (2017) [2] result in higher B/C ratios. 

Noise level reduction assumptions 

TNO 2017 [2] presented two different methodologies for calculating reduction in noise levels. 
First, it bases reductions on LDEN values on the CNOSSOS model and then compares these 
results with an alternative methodology aimed at better capturing the impact of single events. 

The current study presents a mixed model (see section. Noise level data sources). It has been 
considered that the  CNOSSOS  method  is  the  one  that  best represents noise levels  of  total 
traffic  by  reducing  noise  levels  in  L-category  vehicles  in  the  urban  environment.  Also,  the 
percentage of illegal vehicles in urban areas is assumed to be lower, at 12.5%. 

On the other hand, to better reflect the differences in behaviour in rural areas, a methodology 
aimed at better capturing the impact of single events has been used. 

Exposed populations 

In TNO  2017 [2], all  costs  and  benefits  are  being  calculated for the  EU28  including  the  UK 
while in the present study, these calculations have been carried out without the UK. 

Further, there are slight differences in the exposure factor to L-category vehicles’ noise. The 
TNO 2017 [2] study applied exposure factors that consider: 

  A factor of 20% representing weather and a mainly recreational weekend use (touring 

routes) in northern EU Member States. 

  A factor of 50% representing the percentage of roads of Southern EU Member States 

that are affected by the noise level reduction of L-category vehicles. 

  A factor of 8.25% representing exposure in rural areas. 

The reduction factor used by TNO (2017) [2] is 20% for the northern countries and 25% for the 
southern countries. 

In the present study, the exposure levels are: 

  A  factor  of  20%  will  be  used  to  calculate  the  exposure  levels  of  the  population  of 

northern EU Member States in urban areas and 8% for rural areas. 

  A  factor  of  30%  will  be  used  to  calculate  the  exposure  levels  of  the  population  of 

southern EU Member States in urban areas and 8% for rural areas. 

 

Table 42: Differences in exposure levels 

Northern EU 

Sourthern EU 

Urban exposure % 

TNO (2017) [2] 
≈ 20% 

Rural exposure % 

8.25% 

Present study 

20% 

8% 

TNO (2017) [2] 
≈ 25% 

8.25% 

Present study 

30% 

8% 

 
 
 
 
 
 
 
Unit costs 

The table below summarises the differences in health and annoyance unit costs between TNO 
2017 [2] and the present study. 

Table 43: Differences between costs TNO 2017 [2] – Present study 

TNO 2017 [2]  Present study 

Δ€ 

Δ% 

Health benefits (€/person) 

Amenity benefits (€/person) 

Manufacturer costs -2dB (€/unit) 

Manufacturer costs -4dB (€/unit) 

R&D costs -2dB (€/unit) 

R&D costs -4dB (€/unit) 

7.26 € 

12.21 € 

36.52 € 

49.60 € 

3.45 € 

8.61 € 

4.34 € 

-2.92 € 

-40% 

25.35 € 

+13.14 € 

+108% 

32.99 € 

-3.53 € 

-10% 

73.04 € 

+23.44 € 

+47% 

49.56 € 

+46.11 €  +1,337% 

123.90 €  +115.29 €  +1,339% 

Total Authorities cost (0% IL) 

51.0 M€ 

44.3 M€ 

-6.7 M€ 

-13% 

More recent sources (EU 2019) [5] of the unit cost values of the benefits for noise reduction 
present a lower price for health benefits and a higher price for amenity benefits. The value of 
the average amenity benefits is double compared to that of the 2017 study. 

Industry costs show a slight deviation in manufacturing, which increases for the -4dB scenario, 
and a large deviation in research & development (R&D) costs. For this study, manufacturers 
have provided R&D costs about 10 times higher compared to the numbers provided as part of 
TNO 2017 [2]. 

Differences in authorities’ costs come from considering EU27 instead of EU28. 

194 

 
 
 
 
4.5. Conclusions 

 

In scenarios A, B and D, there are positive NPVs and benefit-cost ratios higher than 1, 
suggesting  that  these  policy  options  for  reducing  the  noise  produced  by  L-category 
vehicles are socially beneficial. 

o  The  high  impact  of  enforcing  current  or  future  limits  on  benefits  stands  out. 
Much of the noise reduction in rural areas is due to substantially reducing or 
eliminating vehicles that violate current noise limits. 

o  With the single event calculation methodology for rural environments, greater 
weight is given to these circumstances than in the methodology used in TNO 
(2017) [2]. 

  There are parameters that pose uncertainty. 

o  For manufacturing and research and development R&D costs, there is not much 
specific  data  available  in  the  public  domain.  The  estimations  are  exclusively 
based on information provided by industry. 

o  Enforcement:  There  is  little  evidence  available  in  the  public  domain  on  the 
actual effort required to reduce illegal vehicles from the roads. In addition, it has 
not been able to obtain reliable estimates for actual shares of illegally modified 
L-category vehicles in both, urban and rural environments. 

  Having a sub-scenario that includes 5% of remaining illegally modified vehicles is more 
realistic than going from 25% to 0%. Although enforcement is increased, there may be 
users  who  have  modified  vehicles  that  do  not  comply  with  regulations,  especially 
outside urban areas, where controls may not be as exhaustive. 

 

In Scenario D, the progressive implementation of limits entails higher benefits at a lower 
cost to afford a 4dB limit reduction. Compared to Scenario C, industry is given more 
time to adapt to -4dB regulation levels. 

 
 
 
 
 
5. Proposal for limit values 

Based  on  the  outcomes  of  the  previous  tasks  and  the  feasibility  and  viability  of  the  new 
potential sound limits as past of the CBA, this task presents the proposal for sound level limits. 

5.1. General conclusions 

5.1.1. Scenario A: 0 dB reduction (Lurban) – Increased enforcement 

only: 

L3e (UN-Reg. 41.04): 

73 dB(A): PMR ≤ 25 

74 dB(A): 25 < PMR ≤ 50 

77 dB(A) : PMR > 50 

L2e, L4e, L5e-A, L5e-B, L6e-A, L6e-B, L7e-A, L7e-B, L7e-C (UN-Reg. 9.08): 

76 dB(A): L2e 

80 dB(A): L4e, L5e-A, L5e-B, L6e-A, L6e-B, L7e-A, L7e-B, L7e-C 

Considerations: 

  The stakeholders’ feedback gathering, highlighted factors such as tampering vehicles, 
illegal  NORESS  and  reckless  driving  as  the  main  reasons  of  producing  the  highest 
noise annoyance on public roads. 

  Most of the tested L3e category vehicles with PMR ≤ 50 are in the thresholds of CoP 

sound level limits. 

  L3e with PMR > 50 category vehicles considered in this study are within the approval 

sound level limits. 

  The high performance engine L3e-A3 category vehicles with PMR > 50 are near the 

approval sound level limits (less than 1 dB(A)). 

  L5e-B, L5e-A, L6e-BP, L6e-BU and L7e-CP category vehicles considered in this study 

are within the approval sound level limits. 

  L7e-B1 and L7e-B2 category vehicles considered in this study are in the thresholds of 

approval sound level limits. 

  Highest B/C ratio (2.6) among all other scenarios for 0% of remaining illegally modified 
vehicles  (tampering).  However,  the  enforcement-only  scenario  generates  least  total 
benefits  in  absolute  value  amongst  all  analysed  scenarios.  The  high  B/C  ratio  is 
achieved through comparatively low costs. 

  The new RD-ASEP procedure on UN-R41.05 adds new real driving conditions to be 

tested on a higher control boundary range. 

 

In the  near future  it  is  expected  an  increase of the  electric  L-category fleet  thus the 
decreasing of internal combustion engines. 

  Feasible for all L-category vehicles evaluated within this study. 

196 

 
 
5.1.2. Scenario B: 2 dB reduction (Lurban) – Moderate: 

L3e (UN-Reg. 41.04): 

71 dB(A): PMR ≤ 25 

72 dB(A): 25 < PMR ≤ 50 

75 dB(A) : PMR > 50 

L2e, L4e, L5e-A, L5e-B, L6e-A, L6e-B, L7e-A, L7e-B, L7e-C (UN-Reg. 9.08): 

74 dB(A): L2e 

78 dB(A): L4e, L5e-A, L5e-B, L6e-A, L6e-B, L7e-A, L7e-B, L7e-C 

Considerations: 

  The stakeholders’ feedback gathering highlights that the reduction up to 2 dB(A) is not 
desired for L3e-A3, however is more feasible for tricycles and quadricycles L- category 
vehicles. 

  For L5e-A,L5e-B, L6e-BU, L6e-BP and L7e-CP category vehicles, excluding L7e-B1 
and L7e-B2 (ATVs), will be feasible to reduce 2 dB(A). These reductions in the vehicle 
components can be achieved through an evolutive design process keeping the same 
basic technology concept in the vehicle parts. 

  Some tested L3e vehicles with PMR > 50 depending on the engine configuration and 
power-torque curve are below the approval limits. (More than 2 dB(A) difference). It is 
feasible  since  achieve  these  noise  reductions  in  the  vehicle  components  can  be 
achieve  through  an  evolutive  design  process  keeping  the  same  basic  technology 
concept in the vehicle parts. 

  B/C ratio of 1.4 is lower than in scenario A but provides around 70% more total benefits. 

However, these benefits come at a higher cost. 

  A 2 dB (A) reduction scenario provides more certainty around costs, especially those 
assumed by industry, compared to the 4 dB reduction. This is due to technical solutions 
already available or current components allowing for slight modifications enabling such 
a reduction. 

  A reduction of 2 dB(A) in the Lurban limit, for a high performance L3e-A3 with PMR > 50, 
estimates a required sub-category worst-case reduction* of 6 dB(A) of engine and  6 
dB(A)  in  exhaust  system  contributions  respectively.  A  limited  feasibility  could  be 
considered  on this  scenario  which it  might  imply  technology  changes  whose  cost  or 
technical difficulty could prevent its practical materialisation. 

  A  reduction of  2 dB(A)  in  the  Lurban  limit  for  L3e category  vehicles with PMR  ≤  50  is 
unfeasible. Most of this category vehicles are within the thresholds of the actual sound 
approval limit (74 dB(A)). Assuming this vehicle configuration is usually low-cost, this 
level of noise reduction in vehicle components normally involves disruptive technical 
changes in the corresponding component design concept. Therefore the technological 
uncertainty  associated  to  these  levels  of  noise  reductions  is  very  high  in  both,  the 
required effort and the potential degree of achievement. 

  Feasible for L5e-A,L5e-B, L6e-BU, L6e-BP and L7e-CP category vehicles evaluated 

within this study. 

 
 
*: The term ‘Sub-category average reduction’ for 2 dB(A) or 4 dB(A) refers to the attenuation 
levels for the exhaust system and the engine in figures 97 to 103, presented in Task 3, that 
are associated to values of LUrban whose average is closer to 2 or 4 dB(A), respectively. 

5.1.3. Scenario C: 4 dB reduction (Lurban) – Ambitious: 

L3e (UN-Reg. 41.04): 

69 dB(A): PMR ≤ 25 

70 dB(A): 25 < PMR ≤ 50 

73 dB(A) : PMR > 50 

L2e, L4e, L5e-A, L5e-B, L6e-A, L6e-B, L7e-A, L7e-B, L7e-C (UN-Reg. 9.08): 

72 dB(A): L2e 

76 dB(A): L4e, L5e-A, L5e-B, L6e-A, L6e-B, L7e-A, L7e-B, L7e-C 

Considerations: 

  The stakeholders’ feedback gathering, does not consider a reduction of 4 dB(A). 

  B/C ratio of below 1. There are more costs than benefits mainly due to costs for R&D 
and manufacturing to be assumed in first years while benefits start to kick in only after 
5 years. 

  A reduction of 4 dB(A) in the Lurban limit, for a high performance L3e-A3 with PMR >50, 
estimates  a  required  sub-category  reduction  9  dB(A)  in  the  engine  and  9  dB(A)  in 
exhaust system contributions, respectively. It is considered as an unfeasible scenario. 
This sound level reduction in vehicle components normally involves disruptive technical 
changes in the corresponding component design concept. Therefore the technological 
uncertainty  associated  to  these  levels  of  noise  reductions  is  very  high  in  both,  the 
required effort and the potential degree of achievement. 

  A reduction of 4 dB(A) in the Lurban limit, for bodied tricycles (L5e-B), is feasible. This 
means  that  these  reductions  in  the  vehicle  components  can  be  achieve  through  an 
evolutive  design  process  keeping  the  same  basic  technology  concept  in  the  vehicle 
parts. 

  A  reduction  of  4  dB(A)  in  the  Lurban  limit,  for  unbodied  tricycles  (L5e-A),  estimates  a 
required  sub-category  average  reduction  of  6  dB(A)  in  the  engine  and  0  dB(A)  in 
exhaust system contributions. It is limited feasible to achieve this scenario. These noise 
level reductions might imply technology changes whose cost or technical difficulty could 
prevent its practical materialisation. 

  A reduction of 4 dB(A) in the Lurban limit, for L6e-BP, L6e-BU and L7e-CP is feasible to 

achieve this scenario. 

5.1.4. Scenario D:  4  dB  reduction:  2  dB  reduction  in  2024  +  2  dB 

reduction in 2026 (Lurban) – Stepwise: 

Step 1 (Year 2024) 

L3e (UN-Reg. 41.04): 

71 dB(A): PMR ≤ 25 

198 

 
 
72 dB(A): 25 < PMR ≤ 50 

75 dB(A) : PMR > 50 

L2e, L4e, L5e-A, L5e-B, L6e-A, L6e-B, L7e-A, L7e-B, L7e-C (UN-Reg. 9.08): 

74 dB(A): L2e 

78 dB(A): L4e, L5e-A, L5e-B, L6e-A, L6e-B, L7e-A, L7e-B, L7e-C 

Step 2 (Year 2026) 

L3e (UN-Reg. 41.04): 

69 dB(A): PMR ≤ 25 

70 dB(A): 25 < PMR ≤ 50 

73 dB(A) : PMR > 50 

L2e, L4e, L5e-A, L5e-B, L6e-A, L6e-B, L7e-A, L7e-B, L7e-C (UN-Reg. 9.08): 

72 dB(A): L2e 

76 dB(A): L4e, L5e-A, L5e-B, L6e-A, L6e-B, L7e-A, L7e-B, L7e-C 

Considerations: 

  The stakeholders’ feedback gathering, does not consider a reduction of 4 dB(A). 

  Although this scenario has a similar B/C ratio as scenario B, with 1.4, there is much 
more uncertainty around industry costs and technical feasibility, especially with respect 
to the second step towards a 4 dB(A) reduction. 

  Even taking more time than Scenario C for the reduction by 4 dB(A), there are the same 

technical and cost difficulties to achieve a 4dB(A) reduction of Lurban. 

Step 1 (Year 2024) 

  For L5e-A,L5e-B, L6e-BU, L6e-BP and L7e-CP category vehicles, excluding L7e-B1 
and  L7e-B2,  will  be  feasible  to  reduce  2  dB(A).  These  reductions  in  the  vehicle 
components can be achieved through an evolutive design process keeping the same 
basic technology concept in the vehicle parts. 

  Some tested L3e vehicles with PMR > 50 depending on the engine configuration and 
power-torque curve are below the approval limits. (More than 2 dB(A) difference). It is 
limited feasible since achieve these noise reductions might imply technology changes 
whose cost or technical difficulty could prevent its practical materialisation 

  A reduction of 2 dB(A) in the Lurban limit, for a high performance L3e-A3 with PMR >50, 
estimates a required sub-category average reduction* of 3 dB(A) of engine and 3 dB(A) 
in exhaust system contributions respectively. A limited feasibility could be considered 
on  this  scenario  which  it  might  imply  technology  changes  whose  cost  or  technical 
difficulty could prevent its practical materialisation. 

  A  reduction of  2 dB(A)  in  the  Lurban  limit  for  L3e category  vehicles with PMR  ≤  50  is 
unfeasible. Most of this category vehicles are within the thresholds of the actual sound 
approval limit (74 dB(A)). Assuming this vehicle configuration is usually low-cost, this 

 
 
 
 
 
level of noise reduction in  vehicle components normally involves disruptive technical 
changes in the corresponding component design concept. Therefore the technological 
uncertainty  associated  to  these  levels  of  noise  reductions  is  very  high  in  both,  the 
required effort and the potential degree of achievement. 

Step 2 (Year 2026) 

  A reduction of 4 dB(A) in the Lurban limit, for a high performance L3e-A3 with PMR >50, 
estimates  a  required  sub-category  reduction  9  dB(A)  in  the  engine  and  9  dB(A)  in 
exhaust system contributions, respectively. It is considered as an unfeasible scenario. 
This sound level reduction in vehicle components normally involves disruptive technical 
changes in the corresponding component design concept. Therefore the technological 
uncertainty  associated  to  these  levels  of  noise  reductions  is  very  high  in  both,  the 
required effort and the potential degree of achievement. 

  A reduction of 4 dB(A) in the Lurban limit, for bodied tricycles (L5e-B), is feasible. This 
means  that  these  reductions  in  the  vehicle  components  can  be  achieve  through  an 
evolutive  design  process  keeping  the  same  basic  technology  concept  in  the  vehicle 
parts. 

  A  reduction  of  4  dB(A)  in  the  Lurban  limit,  for  unbodied  tricycles  (L5e-A),  estimates  a 
required  sub-category  average  reduction  of  6  dB(A)  in  the  engine  and  0  dB(A)  in 
exhaust system contributions. It is limited feasible to achieve this scenario. These noise 
level reductions might imply technology changes whose cost or technical difficulty could 
prevent its practical materialisation. 

  A reduction of 4 dB(A) in the Lurban limit, for L6e-BP, L6e-BU and L7e-CP is feasible to 

achieve this scenario. 

200 

 
 
 
 
 
 
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[9]  ACEM,  «ACEM  comments,  questions  and  positions  of  EC  sound  level  study  (Euro  5),» 
2018. 

 
 
 
 
GETTING IN TOUCH WITH THE EU 

In person 

All over the European Union there are hundreds of Europe Direct information centres. You can find the 
address of the centre nearest you at: https://europa.eu/european-union/contact_en 

On the phone or by email 

Europe Direct is a service that answers your questions about the European Union. You can contact 
this service: 

– by freephone: 00 800 6 7 8 9 10 11 (certain operators may charge for these calls), 

– at the following standard number: +32 22999696, or  

– by email via: https://europa.eu/european-union/contact_en 

FINDING INFORMATION ABOUT THE EU 

Online 

Information about the European Union in all the official languages of the EU is available on the Europa 
website at: https://europa.eu/european-union/index_en 

EU publications 

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Multiple copies of free publications may be obtained by contacting Europe Direct or your local 
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EU law and related documents 

For access to legal information from the EU, including all EU law since 1952 in all the official language 
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Open data from the EU 

The EU Open Data Portal (http://data.europa.eu/euodp/en) provides access to datasets from the EU. 
Data can be downloaded and reused for free, for both commercial and non-commercial purposes. 

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ISBN 978-92-76-49856-8