PROPOSAL FOR A COUNCIL DIRECTIVE AMENDING DIRECTIVE 77/143/EEC ON THE APPROXIMATION OF THE LAWS OF THE MEMBER STATES RELATING TO ROADWORTHINESS TESTS FOR MOTOR VEHICLES AND THEIR TRAILERS ( EXHAUST EMISSIONS )
Date: 1991-07-04
Institutions: European Commission
Subjects: approximation of laws, combustion gases, commercial vehicle, motor vehicle, roadworthiness tests

COMMISSION  OF THE EUROPEAN  COMMUNITIES 

C0M(91) 244 final 

Brussels, 4 July  1991 

Proposal  for a 

COUNCIL DIRECTIVE 

AMENDING  DIRECTIVE 77/143 EEC ON THE 

APPROXIMATION OF THE LAWS OF THE 

MEMBER  STATES RELATING TO ROADWORTHINESS TESTS 

FOR MOTOR VEHICLES AND THEIR  TRAILERS 

(EXHAUST EMISSIONS) 

(presented  by the  Commission) 

— 2 -

Explanatory Memorandum 

General Comments 

Actual Situation 

Directive 77/143/EEC*1>, as amended by Directive 88/449/EEC<2>, 

concerns the technical  inspection of heavy goods vehicles, buses, 

taxis, ambulances and light goods vehicles. 

These Directives set the periodicity of tests and provide a list of 

the items to be tested. 

Given that Directive 77/143/EEC does not set standard criteria for any 

of the items that should be tested, it is thus necessary to set common 

minimum test standards in order to guarantee an equal  level of safety 

and through this proposal, environmental performance throughout the 

Community. 

Directive 91/225/EEC<3> amending Directive 77/143/EEC, which was 

recently adopted by the Council, is aimed at the establishment of a 

procedure for the announcement of separate Directives for testing the 

standard of the items listed in Annex  II of Directive 77/143/EEC. It 

also establishes a Technical Committee which gives the Commission the 

mandate to adopt measures in order to adjust the technical 

requirements to progress. 

In line with the above, this new proposal amends Annex  II to Directive 

77/143/EEC as amended by 88/449/EEC so as to better define the limit 

values for the acceptable  levels of gaseous emissions for spark 

ignition (petrol) and smoke opacity for compression ignition (diesel) 

engined motor vehicles. 

(1) OJ No. L47, 18.02.1977, p. 47 

(2) OJ No. L222, 12.08.1988, p. 10 

(3)  OJ No. L103, 23.04.1991, p. 3 

- 3 

Scope of  the proposal 

The scope of Directive 77/143/EEC as amended  by 88/449/EEC  includes 

heavy  and  light commercial  vehicles  (as well  as taxis and  ambulances) 

but  does not  include passenger  cars. Passenger  cars are  the subject of 

an amending  proposal  C0M(86)214<4>. Adoption of C0M(86)214 will 

ensure  that  all motor  vehicles, both passenger  and commercial, are 

subject  to the necessary emission checks. 

This proposal  on  testing  the  level of vehicle gaseous emissions or 

smoke opacity  dovetails  into the current  and proposed  roadworthiness 

schemes and so shares  the same periodicity of  testing. By  the time 

this proposal  is adopted, or soon after, the  legislation  affecting  the 

manufacture of petrol  engined  passenger  cars will  be such as to force 

the use of closed  loop 3way catalytic  converter  systems which  are 

lambda probe controller  for most,  if not  all, new vehicles. The  type 

approval  durability  requirements  for  these vehicle emission  control 

systems would  support  a three year  in use start  point  before  they need 

to be roadworthiness  tested. 

Heavy  commercial  vehicles  (and also taxis and ambulances) will  need  to 

be tested every  year  from  the time of  their  first  use, the diesel 

engined  vehicles  requiring  to demonstrate  their  level of  engine 

maintenance  through  a smoke opacity  check. Light  commercial  vehicles 

(less than 3.5  tonnes) will  require a test  periodicity  of at  least 

commencing  four  years from  first  use and  thereafter  every  two years. 

It  is considered  that  the durability  of diesel  engined  vehicles 

justifies  this periodicity. 

Vehicles  first  used  before  1st  January  1970 will  not  be required  to 

undergo an exhaust  emission or smoke opacity  check. However, Member 

States will  be free to test  these vehicles  to their own national 

standards  if they so wish. 

(4) OJ No. C  133, 31.05.t986, P„ 3 

- 4 -

Limit  values 

After much discussion with Member  States National  experts on 

roadworthiness testing, on vehicle construction standards and with 

representatives from the automobile and vehicle  inspection  industries 

it has been decided  to set maximum vehicle gaseous emission and smoke 

opacity  limit values which will ensure that the "gross polluters" will 

fail  the test.  The  limits for Carbon Monoxide emissions for 

conventional  petrol  engined  vehicles, at 4.5  vol  % and  then 3.5  vol %, 

reflect studies  (in the UK) that have shown that some 50  % of CO emis 

sions comes from  the worst  17 % or so of  the petrol  engined  vehicles 

on  the roads at  the moment.  Whereas those studies have also shown 

that around  25 % of current  in service conventionally engined 

passenger  cars have CO emission values worse  than 4.5  vol %, bearing 

in mind  that  testing commences after  the vehicles are 3 years oids  it 

is anticipated  that an  initial  failure rate of up  to 50 % could be 

expected.  Clearly  it  is in the publics  interest  to ensure  that  their 

vehicles are correctly  adjusted and maintained. 

[As an a I ten  ?ve to the 4.5/3.5 vol % CO  limits, the maximum  content 

of CO  in the exhaust gas at  idling shall  be that  stated by the vehicle 

manufacturer  and recorded at type approval  testing.  This alternative 

is always equal  to or  lower  than the 4.5/3.5 vol %  limit.] 

For petrol  engined  vehicles with advanced emission control  systems, 

ie. with closed  loop 3-way catalytic converter  which  are  lambda  (air/ 

fuel  ratio) probe controlled, the  limit CO valve of 0.3  vol % reflects 

the need  to maintain  the quantum  leap  in vehicle emission  reduction 

brought  about  by the  introduction of  this new  technology. 

For vehicles with diesel  engines this proposal  adopts the philosophy 

of  judging  the maintenance condition of  the vehicle, and hence  its 

ability  to be a  low polluter, by measuring  the opacity of  its exhaust 

smoke. 

-  5 -

The  Mmit  values of  >-.e coefficient of absorption of  the generated 

jmoke of 2.5 m~1  for natural y aspirated  diesel  engines and 3.0 m~1 

for  turbo charged  diesel  engines take account of  the  imprecision of 

the free acceleration  test as a predictor of  in service conditions, in 

particular  for  turbo charged  heavy commercial  vehicles, but are 

sufficiently  tight  to again  identify  the gross polluters, vehicles 

that are responsible  for most of  the pollution emitted  by vehicles  in 

service. 

-  6 • 

PROPOSAL  FOR A 

COUNCIL DIRECTIVE 

AMENDING  DIRECTIVE 77/143/EEC 

ON THE APPROXIMATION OF THE LAWS OF THE 

MEMBER  STATES RELATING TO ROADWORTHINESS TESTS FOR 

MOTOR VEHICLES AND THEIR  TRAILERS 

The Council  of  the European  Communities, 

Having  regard  to the Treaty establishing  the European  Economic 

Community  and  in particular  Article 75 thereof, 

Having  regard  to the proposal  from  the  Commission^1), 

Having  regard  to the opinion of  the European Par I lament*2), 

Having  regard  to the opinion of  the Economic and Social  Committee*3^, 

Whereas, Council  Directive 77/143/EEC(4>  as amended  by Directive 

88/449/EEC<5) provides for  the regular  roadworthiness testing of 

certain  road vehicles only  (buses, heavy and  light goods vehicles, 

heavy  trailers and semi  trailers, taxis and ambulances) but  not yet 

for passenger  cars; 

Whereas,  through Council  Directive 91/225/EEC<6>,  it  is the  intention 

to establish procedures  for  the announcement  of separate Directives 

for  testing  the standard of  the  items  listed  in Annex  II of  the above 

Directives; 

Whereas, through  the above directive  it  is also the  intention  to 

establish  a Technical  Committee which gives the Commission  the mandate 

to adopt measures  in order  to adjust  the technical  requirements  to 

progress: 

(1) OJ N" C  ... 

(2) OJ N* C  ... 

(3) OJ N* C  ... 

(4) OJ N- L47, 18.2.1977, p. 47 

(5) OJ N' L222, 12.8.1988, p. 10 

(6) OJ N' L 103, 23.4.1991, p. 3 

-  7 

Whereas,  by  this  Directive  it  is the  intention  to maintain  the  exhaust 

emission  of  vehicles  at  a  low  level  during  their  useful  life by  means 

of  a periodical  exhaust  emission  test  and  ensure  that  vehicles  which 

are  gross  polluters  are  removed  from  service  until  they  are  correctiy 

maintained  ; 

Whereas,  most  Member  States  have  adopted  procedures  for  testing  heavy 

commercial  vehicles  with  regard  to  the opacity  of  their  exhaust  smoke-, 

Whereas,  several  Member  States  have  national  rules  for  testing  the 

gaseous  emissions  from  lighter  vehicles  including  passenger  cars; 

Whereas,  assessment  of  the  type  approval  testing  for  gaseous  emissions 

and  diesel  smoke  for  all  vehicle  types  shows  that  the  reproduction  of 

those  testing  procedures  within  the  roadworthiness  test  is not 

realist ic; 

Whereas,  standards  that  are  dictated  for  in service  testing  should 

focus  on  the maintenance  condition  of  the  vehicle,  and  thereby  its 

ability  to meet  type  approval  performance  criteria,  during  a 

relatively  simple,  quick  and  inexpensive  test; 

Whereas,  wrong  tuning  of  the engine  and  insufficient  maintenance  are 

detrimental  to  the  engine  and  to  the environment  through  increases  in 

pollution  and  fuel  consumption; 

Whereas,  as  far  as  diesel  engines  (compression  ignition)  are 

concerned,  measurement  of  the opacity  of  the  exhaust  emissions  is 

considered  a  sufficient  indicator  of  the  condition  of  the  vehicles' 

emission  control  system; 

Whereas,  for  conventional  petrol  engines  (spark  ignition)  the 

measurement  of  the  vehicles'  tailpipe emissions  of  carbon  monoxide 

taken  at  engine  idle  speed,  is considered  to give  a  sufficient 

indication  of  the  vehicles  maintenance  condition; 

Whereas,  it  is expected  that  the  failure  rate of  the  above  vehicles 

retating  to  exhaust  emissions  could  be  high  if  the  vehicle  has  not 

been subjected  to routine  marntenance; 

-  S -

Whereas,  for  petrol  engined  vehicles  where- tNo  type  approval  requi 

rements  necessitate  that  they  be equipped  with  advanced  emission 

control  systems  such  as closed  loop, 3way  catalytic  converters  which 

are  lambda  probe  controlled,  the  standard  for  in service  emission 

testing  will  be more  severe  than  for  conventional  vehicles-, 

Whereas,  it  is the  intention  to adapt  this Directive  to  take  account 

of  future  developments on  the provision  of  vehicle  construction 

measures which  facilitate  in service  inspection  and  advances  in 

testing  methodology  designed  to better  reflect  conditions  in service 

Has  adopted  this  Directive. 

Article 1 

1. 

Sub  Paragraph  8.2  of  Annex  II to Directive  77/143  EEC  as  amended 

by  Directive 88/449  EEC which  concerns  exhaust  emissions  is 

replaced  by: 

« 9 

8.2 

Exhaust  Emissions 

8.2.1 

Motor  vehicles equipped with spark  ignition  (petro!) engines 

a) 

where  the exhaust  emissions are not governed  by an advanced 

emission  control  system  such as a closed  loop three way 

catalytic  converter  which  is lambda probe controlled. 

1. Visual  inspection of  the exhaust  system  in order  to check 

that  there are no  leakages. 

2. Visual  inspection of  the emission control  system  if 

applicable  in order  to check  that  the necessary  equipment  is 

present. 

After  a reasonable period of engine conditioning  commensurate 

with  the vehicle manufacturers  recommendations  the carbon 

monoxide  (CO) content  of  the exhaust  gases will  be measured 

at engine  idle speed  (no  load). 

The maximum  allowable  content  of CO  in the exhaust  gases 

shall  be that which  is stated by the vehicle manufacturer  and 

recorded  at  the time of  initial  type approval  with a 

tolerance of 0.5  vol %.  Where  this data  is not  available or 

where Member  States testing  authorities decide not  to use 

this data as a reference value then  the exhaust  gas content 

of CO must  not  be greater  than  the following : 

For vehicles manufactured  prior  to October  1986 or  the date 

on which Member  States  required  the vehicles at  first 

registration  to comply with  the type approval  Directive 

70/220/EEC<7>  as amended  : CO - 4.5 vol  % 

(7) OJ Nr L 76 of 9.3.1970, p. 

-  10 -

For  vehicles manufactured  after  1 October  1986  : 

CO -  3.5  vol  % 

Vehicles manufactured  prior  to  1 January  1970 are  exempted 

from  these  requirements. 

b) 

where  the exhaust  emissions  are governed  by  an  advanced 

emission  control  system  such  as a closed  loop  three  way 

catalytic  converter  which  is  lambda  probe  controlled or  where 

the  vehicles' exhaust  emissions  are governed  by  some  other 

method  in order  to comply  with  the  type  approval  provisions 

of  Directive 70/220/EEC  as amended  [by  the  consolidated 
emissions  Directive*8*]. 

1. Visual  inspection  of  the exhaust  system  in order  to  check 

that  there  are  no  leakages  and  that  all  parts  are  complete. 

2. Visual  inspection  of  the emission  control  system  in order 

to  verify  that  the  necessary  equipment  is present. 

3. Determination of  the efficiency  of  the  vehicles  emission 

control  system  by measuring  the  lambda  value  and  the  CO 

content  of  the exhaust  gases  according  to point  4 below or 

according  to the manufacturers  optional  procedures  as 

recorded  at  the  time of  initial  type  approval.  The  vehicle 

shall  undergo  a period  of  engine  conditioning  commensurate 

with  the  vehicle manufacturers  recommendations  for  each  of 

the  tests. 

4. Tail  pipe  emissions  -  limit  values 

-  Measurement  at  engine  idle speed  ; 

The maximum  allowable  content  in the exhaust  gases  of  CO 

shall  be  that  which  is stated  by  the  vehicle  manufacturer 

and  recorded  at  the  time of  initial  type  approval. 

Where  this  data  is not  available  then  the CO  limit  of  0.5 

vol  X  should  not  be  exceeded. 

(8) Council  N' 4102/91  adopted  by  the Council  on  4 March  1991. 

11 -

Measurement at  increased  idling speed without engine  load 
engine speed  to be at  least  2000 r.p.m. 

CO content  : no greater  than 0.3  vol  % 
Lambda 

: I ±  0.03 or  in accordance with  the 

manufacturers specifications. 

8•2•2 

Motor  vehicles equipped with compression  ignition  (diesel) 
engines 

Measurement of exhaust  gas opacity upon revving  the engine 
with  transmission  in neutral  (no  load),  i.e. the engine  is 
accelerated  from  idling speed up to cut off  speed. The  level 
of opacity  shall  be no more  than that which  is stated  by the 
vehicle manufacturer  and recorded on  the vehicle at  the time 
of  initial  type approval  with a tolerance of 
0.5  m ~1.  Where  this data  is not available or  where 
Member  States testing authorities decide not  to use  this 
value as a reference  than the following  limit values should 
not be exceeded : 

Maximum coefficient of absorption for 

Naturally aspirated  diesel  engines - 2.5 m~1» 
Turbo charged diesel  engines 

• 3.0 m" 

Vehicles manufactured  prior  to 1 January  1970 are exempted 
from these  requirements. 

8.2.3. 

Test  equipment 

The testing of both petrol  engined and diesel  engined 
vehicles will  require the use of equipment  capable of 
accurately  testing vehicles against  the prescribed or  stated 
limit values. 

-M 

-

Article  2 

1.  Member States shall  take the measures necessary  to comply with 

this Directive before 1 January 1993.  They shall  forthwith 

inform the Commission thereof. 

2.  When the Member States adopt the provisions referred  to in 

paragraph 1, these shall contain a reference to this Directive or 

shall be accompanied by such a reference at the time of their 

official  publication.  The form of this reference sha11 be 

decided by the Member States. 

3.  Member States shall communicate to the Commission the provisions 

of national  law which they adopt  In the field governed by this 

Directive. 

Article 3 

This Directive  is addressed to the Member States 

Done at Brussels, 

For the Council 

The President 

Compet i t i veness and Cmplovment  Impact  Statement 

!.  What  is the main reason for  introducing this measure? 

Whereas  the build standard of vehicles, with  regard  to the emissions 

of gaseous pollutants, have  improved over  the years, the ability 

to 

maintain a reasonably  low  level of emissions  from  in service  vehicles 

is tested only  in a few Member  States. It  Is recognised  as being of 

vital  importance  that vehicles continue to produce  levels of 

emissions  in service which can equate  to their original  type approved 

standard. Tests have shown  that vehicles with conventional  petrol 

engines can produce  four  times or more carbon monoxide than they do 

when new  (although  the  level of nitrous oxides tends  to fall slightly 

in service). A simple 

Justment  is invariably  all  that  is required 

to bring  these vehicles back  into tune. Modern petrol  engined 

vehicles with catalytic converters  (with  lambda probe controlled 

air/fuel  ratio) produce  in the order of  1/10  the pollutants of 

conventional  vehicles.  It  is important  that  this  impressive  standard 

is maintained  in service as failure of  the catalyst  through  lead 

poisoning, burn out etc can render  the vehicle worse  than those with 

relatively modern conventional  engines. For diesel  engines, dense 

clouds of smoke are the obvious manifestation of poor  engine 

maintenance. This poor maintenance will  invariably  cause high  levels 

of gaseous emissions  (as well  as soot and other  particulates). Again 

this proposal  aims at  identifying  the gross polluters. 

I I.  Features of  the business  in question 

All  users of vehicles, the subject of Directive 77/143/EEC as 

amended, also garages, technical  services and agencies charged with 

vehicle roadworthiness testing will  be affected. As things stand at 

the moment, only  commercial  vehicles, including  taxis and ambulances, 

are covered  by roadworthiness Directives. 

-  -iq  -

The  amendment  to  include passenger  cars within  a  Community 

roadworthiness  scheme  remains on  the  table  of  the Council.  Until  this 

amendment  is adopted  this proposal  on exhaust  emissions will  not 

affect  owners of  passenger  cars  nor  those  small  businesses  responsible 

for  their  operation  or  maintenance. 

111.What  obligations does  this measure  impose  directly 

on  business? 

Users of  vehicles, be  they  the general  public  or  commercial  operators 

will  need  to pay  particular  attention  to  the  standard  of  maintenance 

of  their  vehicles' emission  control/engine management  systems.  This 

is no more  than  should  reasonably  be  done  anyway  for  both 

environmental  and  fuel  saving  reasons. The  cost  of  the  roadworthiness 

test  may  rise  (by  approximately  20 %)  for  those  Member  States  that  do 

not  currently  test  for  vehicle  emissions. Also,  the  testing 

agencies/garages will  need  to  invest  in equipment  which,  for  testing 

vehicles  with  catalysts  etc. could  cost  a  further  7000  ECU.  However, 

as  yet  passenger  cars will  be unaffected  by  this  proposal  until  they 

are  included  within  the  roadworthiness  scheme. 

IV. What  indirect  obligations  are  national,  regional  or  local 

authorities  likely  to  impose  on  business? 

Implementation  of  the obligations  as described  in  III. 

V. 

Are  there  any  special  provisions  In respect  to  SME's? 

Where  roadworthiness  testing  is delegated  to private  garages,  these 

garages will  incur  an extra  cost  for  test  equipment.  However,  that 

cost  can  be offset  by  increased  fees. 

VI.  What  Is the  likely  effect  on: 

- 4S -

a) 

The  competitiveness of  business 

The  extra  complexity  of  testing  for  exhaust  emissions  will  increase 

the  cost  of  the  roadworthiness  test  for  commercial  vehicle  operators 

by  approximately  20 %.  This will  apply  to passenger  car  operators  as 

and  when  these  vehicles  are  included  in the  roadworthiness  scheme. 

This  proposal  will  equalise  the conditions of  competition  by 

standardising  on  the  type  of  test  to be  applied. 

Certain  EFTA  countries  (Sweden,  Norway,  Switzerland  and  Austria)  carry 

out  or  are  intending  to carry  out  emission  testing  on  the  lines of  the 

proposal. 

b) 

Employment 

Possibly  a marginal  increase  commensurate  with  the  increased  time  to 

test  the  vehicles. 

VII.Have  the  relevant  representation organisations  been  consulted? 

All  Member  States  roadworthiness  testing  authorities,  the 

coordinating  body  of  roadworthiness  testes  (CITA),  DEKRA,  the  garage 

equipment  association  and  private  testing  organisations  have  been 

consulted. 

ISSN 0254-1475 

COM(91) 244 final 

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