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COM (84) 523 
 
 
 
Vol. 1984/0 207 
  
 
Disclaimer  
Conformém ent au règlement (CEE, Euratom) n° 354/83 du Conseil du 1er février 1983 
concernant l'ouverture au public des archives historiques de la Communauté économique 
européenne et de la Communauté européenne de l'énergie atomique (JO L 43 du 15.2.1983, 
p. 1), tel que modifié par le règlement (CE, Euratom) n° 1700/2003 du 22 septembre 2003 
(JO L 243 du 27.9.2003, p. 1), ce dossier est ouvert au public. Le cas échéant, les documents 
classifiés présents dans ce dossier ont été déclassifiés conformément à l'article 5 dudit 
règlem ent. 
In accordance with Council Regulation (EEC, Euratom) No 354/83 of 1 February 1983 
concerning the openi ng to the public of the historical archives of the European Econom ic 
Community and the European Atomic Energy Communit y (OJ L 43, 15.2.1983, p. 1), as 
amended by Regulation (EC, Euratom) No 1700/2003 of 22 September 2003 (OJ L 243, 
27.9.2003, p. 1), this f ile is open to the public. Where necessary, classified documents in this 
file have been declassified in conformity with Article 5 of the aforementioned regulation.  
In Übereinstimmung mit der Verordnung (EWG, Euratom) Nr. 354/83 des Rates vom  1. 
Februar 198 3 über die Freigabe der historischen Archive der Europäischen  
Wirtschaftsgemeinschaft und der Europäischen Atomgem einschaft (ABI. L 43 vom  15.2.1983,  
S. 1), geändert durch die Verordnung (EG, Euratom) Nr. 1700/2003 vom 22. Septem ber 2003  
(ABI. L 243 vom 27 .9.2003, S. 1), ist diese Datei der Öffentlichkeit zugänglich. Soweit  
erforderlich, wurden die Verschlusssachen in dieser Datei in Übereinstimmung mit Artikel 5  
der genannten Verordnung freigegeben.  
COMMISSION OF THE EUROPEAN COMMUNITIES
COM(84) 523 final  
Brussels, 28 September 1984
REPORT BY THE COMMISSION TO THE COUNCIL
ON
VEHICLE WEIGHTS AND DIMENSIONS :  DRIVE AXLE WEIGHTS AND RELATED PROBLEMS
COM(84) 523 final

REPORT BY THE COMMISSION 
TO THE COUNCIL
ON
VEHICLE WEIGHTS AND DIMENSIONS: DRIVE AXLE WEIGHTS AND RELATED PROBLEMS

-2-
INTRODUCTION:
1.1 At their meeting on 10th May 1984 the Transport Ministers agreed on a
number of basic elements in the draft directive on weights, dimensions and  
certain related characteristics of certain road vehicles. These were:-
(a) Dimensions
(b) Maximum authorised weights for:
- vehicle combinations with 5 or 6 axles
- trailers with 2 or 3 axles
rigid motor vehicles with 4 axles
(c) Axle weights for:
single non drive axles  
tandem axles  
tridem axles
(d) Other technical standards covered by type approval directives.
1.2 In the conclusions adopted by them they also requested the Commission:-
"To report to the Council before 31st December 1984 on the maximum authorised  
weights to be put into the directive for rigid motor vehicles with 2 axles,  
of different types of vehicles with 3 axles, and of vehicle combinations with  
4 axles, as well as on the problem of the weight of the drive axle". '
This report meets that request.
1.3 It hardly needs to be said that the agreements already reached and listed in  
paragraph 1.1 form a basic platform from which the decision on the remaining  
weights must be taken. The values already have both direct and indirect  
influences on the remaining ones. For example the decision taken to limit the  
maximum gross weight of 5 axled vehicle combinations to 40 tonnes taken together  
with the limit of two axled trailers of 18 tonnes, limits the range of possible  
values for vehicle combinations with 4 axles. Some of the interactions between  
the various weights are shown in Figure 1.
1.4 The Commission's 1979 proposal as amended in 1981 - which is still on the table -  
contained values for all the weights needed in the directive except for the
2 axled solo lorry. These values were based on extensive consultation with  
hauliers, manufacturers, environmentalists and other interested parties. The  
items agreed on so far by the Council are in line with the values proposed by  
the Commission. What this paper will do, therefore, is to review the undecided  
weights, both as regards the way in which they were originally derived and any  
new arguments advanced or information obtained since then, to check whether the  
Commission's proposal should be reconsidered.
_ _
Council Doc. Document de séance TRANS/84/31 of 14.5.1984.

-3-
FIGURE I
INFLUENCE OF COUNCIL'S AGREEMENT ON OTHER VEHICLE TYPES + DRIVE AXLE
Decision
40
18tns
tns5 ax Le 
2 axle
24 tns 3 axle  
+ tandem axle  
+ tridem axle etc.
I}
Drive axle
-4 Indirect influence.  
-> Direct influence4 axle vehicle  
combined
2 axle rigid
3 axle rigid
1.5 Before doing so, however, it is necessary to emphasise that any solution must  
be evaluated in relation to what the directive will achieve. The aim has  
always been and still remains that of defining the characteristics of certain  
vehicles which could be allowed to circulate freely in the Community, in  
particular the heavier combinations commonly used by international traffic.  
More specifically the proposal:
(a) permits vehicles meeting the requirements of the directive to
circulate freely in the Community, in spite of any different and/or  
additional national standards related to weights and dimensions  
which may exist;
(b) permits vehicles meeting the requirements to be sold freely, subject  
however to meeting certain additional national standards related to  
weights and dimensions, if any; in accordance with the rules of the Treaty.
(c) allows existing national standards to remain the same, though in  
practice this will mean that "lower" standards will have to be  
raised to meet those of the directive whilst "higher" standards  
can continue to be utilised nationally;
(d) does not exclude bilateral or multilateral agreements on "higher"  
standards so that e.g. higher drive axle weights or total weights  
could be permitted by States who so agree.

-  4 -
Moreover, agreement on weights and dimensions will reduce the need for  
detailed technical control at frontiers of commercial vehicles in the  
Community and will provide a basis for the growth in the medium and  
longer term of a common market for commercial vehicle manufacturers.
2. EXTENT OF HARMONISATION
2.1 As noted in the introduction, on 10 May 1984 Ministers agreed on a number  
of basic issues which by themselves constitute a step forward towards  
further harmonisation. In today's circumstances, where so many values  
differ between Member States, the agreement already arrived at on  
dimensions, maximum authorised weights for certain vehicles, some axle  
weights and other technical standards covered by type approval directives  
forms a mini-package of harmonisation important for both transport and the  
motor industry.
2.2 It would be highly desirable if this package could be extended to include  
all the weights, particulariy the drive axle weight, necessary to define the  
various types of vehicle. A directive containing all the weights would  
greatly assist hauliers in their choice of vehicle and would, in time,  
enable manufacturers to reduce the number of different specifications of  
vehicle they offer on the European market.
2.3 On the other hand the absence of such a decision, though regrettable,  
would not really make the position of the manufacturers more difficult  
than at present. They already have to cater for quite different markets  
in the Community, with national standards ranging from 10 to 13 tonnes for  
the single drive axle.
3. DRIVE AXLE WEIGHT
Present _s2tuati_on
3.1 Two basically different approaches have been developed in the Member States  
as concerns the weight of the single drive axle:
(a) The first approach emphasises the greater damage that heavier axles
cause to the infrastructure and thus calls for higher design standards  
and costs of bridge construction and road surfacing. Moreover, the  
relatively severe weather conditions which apply in these countries

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aggravate the problems caused by the heavier axles. In these  
countries drive axles today are between 10t (DK,NL,D) and 10,5t  
(UK,IRL) whilst total weights range from 38t (D,UK,IRL) to 48t (DK)  
and 50t (NL).
(b) The second approach gives more importance to vehicle design para­
meters. Infrastructure design and maintenance standards are  
therefore quite high in order to meet the higher axle requirements.
In these countries drive axles range from 12t (I) to 13t (F,GR,B,L)  
whilst the total weight ranges from 38t (F,GR,B,L) to 44 t (I).  
However, in some of these countries the level of infrastructure  
maintenance costs is causing concern and ideas for reducing weights  
are being considered; this is the case in Belgium where a formal  
proposal exists to reduce drive axle weights from 13 to 12 t.
3.2 The difficulty of finding a Community solution for drive axles is no doubt  
due to this basic difference in approach. It should be remembered that
the Commission's original proposal in 1971 proposed a universally applicable  
standard of 11.5t, but at that time the six Member States agreed on 111  
as a compromise. The accession of the three new Member States, who  
favoured lower axle weights prevented agreement on 11 tonnes being reached.  
The latest Commission proposal, put forward in 1979 after a number of  
unilateral changes in national axle weight limits,incorporated moderate  
axle weights including 11t for the drive axle, combined - in the interests  
of operating economy - with relatively high gross vehicle weights.
Itl£_iDiiy£D££_2i_2£iv£_Axle_We22hts_on_Infrastructure  
Road Surface
3.3 The relationship between axle weight and road damage was first established  
by the American AASHO tests which concluded that road damage varied as the  
fourth power of the static axle load. Subsequent studies have shown that  
other vehicle parameters should also be taken into account which may improve  
or worsen the situation. These parameters, which however have never been  
precisely quantified, are:
the quality of the suspension and shock absorbers  
the type and number of tyres per axle  
the tyre contact pressure
factors applicable to tandem or triple axles.

-  6 -
3.4 Concentrating on the damage caused by a single axle and leaving aside  
the above unquantified parameters, Figure 2 clearly shows the
damage effect of different weights of a drive axle (with standard double  
tyres at an inflation pressure of 8.5 bar).
FIGURE No.2 ROAD DAMAGE VERSUS AXLE WEIGHT
Thus it is clear that an 11t axle creates about 45% more damage than  
a 10t axle and an 11.5t axle 75% more. A 12t drive axle doubles and  
a 13t axle almost triples the damage of a 10t axle. These figures may  
be improved by better suspensions or lower tyre pressures, whilst they 
may be worsened if the road surface is uneven.
3.5 There has been some criticism of AASHO results and publicity has been
given to possibly different findings of experiments at NARDO in Italy.  
Whilst these findings can be utilised only in a qualitative manner, due  
to the very high axle and total loads that were tested, it is reassuring  
to note that they are completely in line with the thinking of the Commission  
in making its overall proposal, as the following quotations show:
"NARDO experiments Report No. 3 , p.69.

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- "With the increase in the load per axle and consequently of the
total weight for a given configuration, the pavement life  
decreases notably...."
"As a direct consequence of what was pointed out above the  
aggressivity of the vehicle drops sharply with the increase in  
the number of axles _="
- 
"The twin-wheel axle causes less damage to the pavement than a
single wheel axle. The effect of a single wheel axle of 7 tonnes  
is in fact equivalent to that of a twin-wheel axle of 10.7 tonnes..."
- "The effect of the wide-base tyre can be partially offset only by
adopting a tridem set and restricting the total load to no more  
than 20-24 tonnes"
These findings support the idea that moderate axle loads should be  
chosen for the drive axle.
Effect of drive axle weight on bridges
FIGURE No. 3: EFFECT OF AXLE LOADS ON SHORT SPAN BRIDGES

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3.6 The effect of axle loadings on bridges is different from those on  
pavements. Single axle loads of 1 0 — 11 - 12 - 13 tonnes are only  
significant on shorter spans, for longer spans they are overtaken in  
importance by the loads from axle groups as can be seen from figure No.3.
3.7 With an 111 limit, it is only on bridges with spans of Less than 2m  
that the single axle gives the highest loading. On longer bridges  
the tandem and triaxle loadings which the bridges were designed or  
strengthened to take, predominate. If a 13t limit were chosen,
the single axle~ loading would predominate on spans up to 3.5m and some  
bridges of this kind may have to be strengthened. Since this limit  
includes bridges that are widely used on the secondary network of Member  
States large numbers are likely to be affected.
Effect of drive axle on vehicle design
3.8 The value of the drive axle weight directly influences the rear over­
hang of vehicles. However this influence works in different  
directions for different types of vehicle. On a two axle motor vehicle,  
such as is predominantly used in urban areas, the rear overhang will increase  
as the drive axle weight increases. In contrast, for articulated vehicles  
the rear overhang of the semitrailer decreases with increasing drive axle  
weight. However for 5 axle combinations with 3 axle trailers this will
not be significant if the maximum triaxle weight is used. .  .
3.9 It has been argued that a higher drive axle load would help to achieve  
longer loading spaces on articulated vehicles of 15.5m length. With shorter  
cabs it is possible to lengthen the loading space without cab to trailer  
fouling problems and without exceeding the required turning circle, by moving  
the fifth wheel mounting towards the rear. In the absence of other changes,  
this increases the amount of the imposed load carried by the drive axle,  
implying in turn a higher drive axle load. However the influence on the  
drive axle can be offset by moving the axles of the semitrailer and decreasing  
the load imposed by it on the tractor. With a total weight Limit of 40t  
there is scope for doing this.

- 9 -
Effect of drive axle on operational characteristics
3.10 Hauliers will normally benefit from higher permitted weights and  
dimensions. In the case of axles, higher loads will permit:
more flexibility in loading methods  
lower energy consumption  
less tyre wear.
because a higher drive axle weight may allow a given quantity to be  
transported in a fleet of vehicles with a smaller number of axles in total.
3.11 Heavier drive axles may also improve braking characteristics and, provided 
the higher engine power is not used, help to avoid any malfunctioning such  
as wheel spinning which can happen with inexperienced drivers.
3.12 Finally, heavier drive axles permit higher traction ratios (better adhesion)  
to be achieved. The traction ratio is defined as the relation between the  
drive axle and the total weight of the vehicle or combination. A minimum  
ratio of 25% has been agreed separately as part of the overall package.
Currently minimum traction ratios vary from 20% (NL) to 27.6% (UK,IRL) in  
those countries with low drive axle weight limits to 27.2% (I) to 34.2%  
(F,B,GR) in those with high limits. With an 11t drive axle weight and
the 40t overall vehicle weight limit that has already been agreed, a traction  
ratio of 27.5% is obtained. This is slightly higher than the ratio  
obtained in Italy (27.2%) which is the country currently most concerned with  
this factor.
3.13 Actual traction performance is of course also influenced by the quality of  
the road surface and the condition of the tyres. In icy conditions and  
with worn out tyres even traction ratios of 34% as may be achieved in France,  
Belgium or Greece may not be sufficient. In the Commission's view the  
agreed limit of 25%, which would apply in practice only when transporting  
40ft containers in a 44 tonne total weight vehicle with an 111 drive axle, but  
which normally would be at least 27.5% (11t axle for 40t vehicles) is more  
than sufficient for European conditions.

-  10  -
Problems of Industrial Production
3.14 It has been claimed that manufacturers will have to produce and stock  
a great number of different drive axles if a lower drive axle weight,  
e.g. 11t, is chosen. Not enough evidence to support this view has  
been given particularly when one considers certain manufacturers are  
using only one basic axle with, for example, a capacity of 12t and  
downrating it by using different suspensions and braking systems for  
use in markets with lower limits.. Moreover international hauliers  
tend to buy vehicles with higher technically permissible drive axle  
loads and then plate them with authorised lower weights in the country  
of registration. The actual choice of a particular axle weight is not  
expected to influence the production of the axles themselves to any great  
degree due to the above mentioned reasons and to the fact that the possible  
values suggested so far are in the range of axle weights currently being  
utilised.
3.15 It has also been suggested that the choice of a low drive axle weight  
would increase penetration into the Community market by manufacturers from  
third countries, particularly Japan. This is an argument that can apply
to any harmonisation of standards between the Member States. However, life is  
made easier by this process for all manufacturers, i.e. those within the  
Community as well as outside it. Moreover the national standards in Japan (and  
the USA) are lower than those being considered here and, with the single  
exception of Ireland, the Japanese have not penetrated the Community market  
with axle limits close to their own. It therefore seems highly unlikely that  
the choice of the drive axle weight alone will determine market performance by  
these manufacturers.
3.16 The problem of loss of economies of scale for European manufacturers selling  
in African or Middle East markets where 13 tonne axles are currently used is  
not relevant. In the first place a 13t drive axle has never been seriously  
considered as a possible EC value and secondly even if it were, the
10t agreed for non-motor single axles already means that the vehicles for  
the European and overseas markets must be different.

-  11 -
Influence of drive axle on tandem and triaxles
3.17 Triaxles including a drive axle are not used in normal transport operations  
and in any case are not included in the Annexe to the Directive. They are  
therefore not influenced by the choice of drive axle weight.
3.18 On tandems where double drive is used, the combined weight of the two  
axles does not usually exceed 18t (9t per axle) in normal operating  
conditions. Even this gives a very high traction ratio. Exceptionally  
20t double drive with 10t per axle may be used, but not in countries  
with drive axles weights of 12t and 13t, because there a single drive tandem  
will be used instead, still with a total tandem weight not exceeding 20t.
Cone lusi ons:
3.19 The above analysis has considered a wider range of values for the drive  
axle weight than those worth considering as "compromise" values, taking into  
account the need for a balance between the sometimes conflicting require­
ments of infrastructure. operating economy, vehicle design and other  
manufacturing aspects, etc. In fact, the choice would seem to be restricted  
in practice to 11 or 11.5 tonnes, the former still being considered too high  
at present by some Member States*whi 1st the latter is considered acceptable  
by other Member States who would really prefer 12t.
3.20 The Commission concludes that the arguments advanced by advocates of 11.5t  
are neither new nor sufficient to invalidate the Commission's current  
proposal of 11 tonnes, which it strongly believes to be both the right  
compromise figure and consistent with the decisions taken so far by the  
Council.
4. The 2 Axle Motor Vehicle  
Present situation
4.1 Any decision taken on the drive axle will, of course, have a crucial effect
on the overall weight of a 2 axle motor vehicle. Current standards for these  
vehicles differ substantially between Member States: 16t in D, 16,5 in UK/IRL,
18t in I, and 19t in F, B, L, GR. (The 18t value in NL and DK is theoretical  
at present because 8t steered axles are not being manufactured). The  
alternative configurations possible with a drive axle weight of 11tonnes are

-  12  -
presented in Annex I, together with their respective total weight,  
payload and damage numbers. For comparison the figures for vehicles  
with other axle weights are also shown.
Use of the Vehicles
4.2 Single 2 axled lorries are employed mainly as local distribution vehicles,  
with relatively low powered engines because they are not required to tow  
trailers and excess power would only result in high fuel consumption.
Since the range of payloads for the vehicles currently in use in Europe is  
from 8.9tonnes to 11.6tonnes (calculated from the industry's own formula)  
their use in international transport is very small on cost grounds.
4.3 In contrast the use of 2 axled vehicles as part of road trains is quite usual  
in international transport. These vehicles are however completely  
different, with bigger cabs often with sleeping berths and more powerful  
engines for pulling the heavier loads.
4.4 Because they are hardly used in international transport, the Commission's  
1979 proposal excluded 2 axled solo motor vehicles, whilst including a  
value for such vehicles as part of a road train. A number of delegations  
believe this exclusion would leave an important gap and that solo vehicles  
do play a role in local cross-frontier transport.
Alternative total weights
4.5 The steered axle currently produced by almost all manufacturers does riot  
exceed 6,5 tonnes if the EEC directive on steering effort is to be met.
Only a few manufacturers construct axles with higher than 6.5 tonnes and it  
appears from the NARDO tests that these axles create higher road damage  
than expected.
4.6 Bearing this in mind if the drive axle weight is set at 11 tonnes the  
maximum weight possible for the two axled vehicle would be 17.5t (11 + 6.5t),  
whilst an 11.5t drive axle would allow 18t to be reached.

- 13 -
4.7 Another factor to be considered is the total road damage of these
vehicles, which is well in excess of all others that the Commission has  
proposed, ranging from 14.9 for the 17t (6 + 11) vehicle to 16.0 for the  
17.5t (6.5+ 11) vehicle and 18.0 for the 18t (6.5 + 11.5) vehicle.
Cone lusi ons
4.8 Taking the above considerations into account the final choice should be
limited to vehicles with total weight of less than 18t. With a drive axle  
of 11t, the maximum weight cannot exceed 17.5t, but to give some loading  
flexibility and because these vehicles have the highest damage numbers, 17t  
might well be the best compromise.
5. The 3 axle Motor Vehicle
Present Situation
5.1 Today's standards differ substantially between Member States, ranging from  
22t (D) to 24t (DK,IRL,I,UK) to 26t (B,GR,L,F), with a possible increase  
up to 27 tonnes in NL.
In some of these States the tandem axle is required to be of double drive  
(6 x 4), whilst operators in other States use a retractable back axle and  
single drive vehicle.
As for 2 axled lorries, these vehicles when single are used for local  
transport mainly, with smaller engine outputs. When used for intei  
national transport as part of combinations their construction is different  
with longer sleeper cabs and bigger engines to pull the extra weight.
5.2 The Commission has proposed 24t total weight for these vehicles, but with
different drive axle weights: 10t for single vehicles and 11t for
vehicles forming part of a combination, so that the traction ratio would  
be 27.5% (11/40).
(1)In assessing road damage on an overall basis, allowance must be made for  
the fact that "heavier" vehicles can carry greater loads so that the number  
of vehicles for a given tonnage would decrease. Road damage per vehicle  
should therefore also be related to the tonnage transported. This parameter  
was taken into account in the Commission's proposal and damage numbers -hrun  
here are those derived from the fourth power calculation < ’ p.6) adjusted to  
show damage per 100 tonnes of load capacity.

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The effect of the Council's agreement
5.3 The Council has agreed on a total weight of 40t for 5 or 6 axle road  
trains, 44 tonnes being reserved for semitrailer combinations carrying  
40ft ISO containers. It has also specified a maximum weight of 18t  
for 2 axle trailers and 24t for 3 axle trailers. Specifying 24t for  
the 3 axle vehicle would theoretically allow total combination weights  
on 5 axles of 42 (24 + 18) and up to 48 (24 + 24) for 6 axles. As a  
result, operators would have loading flexibility of 2 to 8t (according  
to the combination) which could be taken off the lorry or the trailer or  
both. The 40t limit means that 24t for the lorry is quite sufficient  
as part of a combination. From an operational point of view it is  
preferable to have single vehicles at the same limit.
Alternative total weights
5.4 Annex II presents alternative configurations of 3 axle motor vehicles with
their total weight, useful payload and road damage numbers. It also shows
that double drive configurations cause less road damage than single ones
because the drive axle weight never exceeds 10t. The combination of 24t
with 11t drive axle keeps the road damage number below 12. For bridges it
(1)has been shown in an earlier Commission report that such a vehicle  
will not impose the heaviest loading on any bridge span. However, a 3 axle  
vehicle with higher total or drive axle weights would be the crucial factor  
for bridge spans between 7-5 and 10m.
Conelusions
5.5 The current Commission proposal of 24 tonnes is the best compromise.
6. THE 4 AXLED COMBINED VEHICLE
Present Situation
6.1 Today's standards differ widely between Member States. At one end of the  
scale are countries where the road damage characteristics of these vehicles  
are the dominant factor, like UK, IRL with 32.5t and D: 32t. In NL and DK  
where only the axle limit is specified 36.5 to 37t are possible and at the  
opposite end we have F,B,L,GR at 38t and I at 40t.
VII/50/81 Rev. 1  of 22 May 1981 Report on "The relationships between axLe  
weight and axle spacing for tandem and tri-axles and between gross vehicle  
weight and overall wheelbase".

- 15 -
6.2 Council decisions on 5 axle combinations at 40t, 2 axle trailers at 18t,  
wide tandem axles at 20t and, last not least, a decision on the drive  
axle all have their effect on the maximum weights of this combination.
In the first place there needs to be a sufficient difference in payload  
between the 4 and 5 axle combinations to compensate for the extra  
purchase and running cost of the latter. Secondly road damage for a
4 axled combination should as far as possible also be close to the values  
for the 5 axle vehicle.
6.3 Annex III presents all possible combinations for 4 axled vehicles from
32 to 4Qt. However, depending on the drive axle value chosen, the two-axle  
vehicle would have a maximum of 17,5t with an 11t drive (or 18t with 11,5t  
drive). Taken together with the above trailer/tandem limits possible maximum  
weights for 4 axled combinations are as follows:
road trains 35.5t (17.5+18) to 36t (18+18)
articulated combinations 37.5t (17.5+20) to 38t (18+20)
Alternative Solutions
6.4 The choice of the appropriate compromise value must also take into account  
that in some Member States, the 4 axled road train is the vehicle that is  
in predominant use; in other Member States it is the 4 axled articulated 
vehicle. To avoid causing distortion in the market there should be no  
difference in the maximum weights permitted for the two types of vehicle.
6.5 Following this argument, the choice is reduced to the range of maximum
35.5 to 36t, which also takes into account the relatively high road damage  
of weights exceeding 36t. Even these values do not allow for the desirable  
flexibility in loading such combinations which is one of the reasons for the  
Commission's present proposal of 35t.
Conclusions
6.6 For a drive axle weight of 11t the Commission proposal of 35t is the most
appropriate figure for four-axled combined vehicles. If the 2 axle vehicle
limit is set at 17.5t, this could be raised to 35.5t. Any increase beyond
this figure would have to be considered in the light of the road damage
(1)effects of a heavier steering axle
d )NARDO experiments have shown substantial road damage differences between  
6t and 7t single tyre axles, which may be greater than those shown in  
the table.

- 16 -
7. TECHNICAL PROGRESS, TOLERANCES/ TRANSITIONAL PERIODS
7.1 Any agreement at Community level should be such as to leave room for its  
adaptation to technical progress.  Improvements in manufacturing and  
operating techniques should not be blocked by rigid legal constraints.
One way in which this is open in the field of weights and dimensions is  
the possibility of "more generous" national standards being applied, as  
noted in Chapter 1.
7.2 A second possibility would be to consider whether to allow such standards
at EEC level on condition that the technical improvements achieved would  
satisfy at least one of the major aims of the overall compromise. Taking  
drive axles as an obvious example, a future 12t axle with improved  
suspension might cause the same road damage or even less than today's 11t  
axle with conventional suspension. It would still be a matter for
decision as to whether
a) such improvements should be fully reflected in standards, or
b) advantage should be taken of them to reduce road maintenance  
and maintenance costs, or
c) a combination of both should be admitted.
7.3 a different suggestion has been to employ tolerances to the values  
laid down. For example, it has been suggested that the drive axle  
might be 11 tonnes with a 5% tolerance, so that 11.5 tonnes would fall  
within the permitted range. The difficulty here is that a number of  
Member States would not be able to use this approach in domestic  
legislation; in such Member States tolerances could only be used at  
the time of inspection on the road and this is indeed frequently exercised  
in practice. A tolerance range at Community level would raise serious  
problems for the sale and registration of vehicles; Member States which  
allowed 11 tonne axles nationally, based on the value chosen, would not  
grant approval to 11.5t axles and this could result in problems for the  
import of vehicles from manufacturers in Member States where 11.5t was the  
accepted figure.

- 17 -
7.4 Finally a brief comment is appropriate on the timing of the measures. Some  
manufacturers have stated that they will need to adapt their vehicle designs  
as a result of the agreed values and this will involve more time and invest­
ment than their competitors may require. The Commission is unable, for lack  
of precise information, to evaluate these statements in a concrete manner-  
Attention needs to be drawn, however, to the provision that all weight  
standards in the proposed directive will come into force only after 5 years,  
which period should suffice for the adaptation process.
8. CONCLUSIONS
8.1. This report has reviewed the arguments advanced by some of the parties  
concerned in favour of heavier axle loads and heavier total weights for  
certain vehicles than those included in the Commission's proposal. In  
so doing it has not dealt in detail with arguments advanced by others in  
favour of lower values, but it should not be forgotten that these were  
used similarly in arriving at the compromise figures put forward.
8.2. Taking the various elements of infrastructure (roads and bridges),  
operating and manufacturing interests, energy, the environment and differences  
in the current situations of the Member States into account, no new or  
different arguments have been advanced of such significance as to invalidate  
the Commission's existing proposals.
8.3 it is therefore suggested that the Council should agree on
11 tonnes for the drive axle weight
17 ........ solo 2 axle motor vehicle
24
 ........ solo 3 axle motor vehicle
35
 ........ 4 axle combination.
If
 political agreement can be obtained only by increasing the values of  
the 2 axled vehicle to 17.5t and the 4 axle combination to 35.5t, such  
values would, in the Commission's opinion, not conflict significantly  
with a technically balanced overall compromise.

ROAD DAMAGE OF 2 AXLE MOTOR VEHICLES (17 - 19t total weight)
IN RELATION TO DRIVE AXLE WEIGHT
Drive axle weight>

ROAD DAMAGE OF 2 AXLE MOTOR VEHICLESANNEX
Total Configuration Payload Number of Damage Number:
Vehi c le (axle loads - t) (t) Standard 10t Standard axles
Weight (+) axles per 1Q0t payload
16 610 8,9 1,130 12,7
16,5 610,5 9,35 1,345 14,4
6,510 1,178 12,6
17 611 9,8 1,464 14,9
512 2,123 21,7
6,510,5 1,394 14,2
710 1,24 12,7
5,511,5 1,839 18,8
17,5 7,510 10,25 1,316 12,8
710,5 1,455 14,2
6,511 1,642 16
6,011,5 1,878 18,3
5,512 2,163 21,1
18 810 10,7 1,409 13,2
7,510,5 1,532 14,3
711 1,704 15,9
6,511,5 1,927 18
6,012 2,203 20,6
5,013 2,916 27,2
18,5 7,511 11,15 1,78 16
711,5 1,989 17,8
6,512 2,25 20,2
5,513 2,946 26,4
19 7,511,5 11,6 2,065 17,8
712 2,313 20
613 2,985 25,7

ROAD DAMAGE OF 3 AXLE MOTOR VEHICLES (24 - 26t total weight)
IN RELATION TO DRIVE AXLE WEIGHT
Drive axle weight

ANNEX
ROAD DAMAGE OF 3 AXLE MOTOR VEHICLES
Total Configuration Payload Number of Damage Number:
Vehi c le (axleloads -■  t)(t)Standard 10t Standard axles
Weight (+) ax les per 100t payload
A. Single Drive (6x 2)
22 610613,7 1,259 9,2
6115 1,654 12
23 610714,55 1,37 9,4
6116 1,723 11,8
24 610815,4 1,54 10
6,510,57 1,634 10,6
6117 1,834 11,9
611,56,5 2,057 13,4
6126 2,333 15,1
613,55 3,045 19,8
25 610916,25 1,796 11
6118 2 12,3
6,5117,5 1,959 12,1
7117 1,944 12,0
6127 2,443 15,0
6,5126,5 2,43 15,0
6136 3,115 19,2
26 6101017,1 2,130 12,4
6119 2,25 13,1
6128 2,613 15,3
7127 2,554 14,9
6137 3,226 18,9
B. Double Drive (6x 4)
22 68,8 13,3 0,95 7,1
23 68,58,514,2 1,173 8,2
24 69915,1 1,442 9,5
78,58,515,1 1,284 8,5
25 69,59,51 b 1,759 11
79916 1,552 9,7
26 6101016,9 2,93 12,6

ANNEX
ROAD DAMAGE OF 4 AXLE COMBINED VEHICLES
Total 
Vehi c le 
Weight (+)Ccnf i  gurat icn 
(axle loads - t)Pay load 
(t)Number of 
Standard 10t 
axlesDamage Number: 
Standard Axles 
per 100t payload
32 6108821,6 1,349 9
32,5 610,58822 2,164 9,8
33 6 11 8 8 22,4 2,413 10,8
34 6 10,58,758,75 23,2 7,517 10,8610,57,510 2,66 11,5Artic 6 118,58,5 2,64 11,4611y10 2,83 12,261288 3,092 13,0
35 Artic 6109,59,524 2,76 11,5Artic610,59,259,25 2,809 11,761199 2,9 12,1611,58,758,75 3,05 12,76,511,58,58,5 2,97 12,46128,58,5 3,247 13,561388 3,8 15,9
35,5 Årti c 6109,759,7524,4 2,98 12,2Artic6119,259,25 3,05 12,56,51199 2,95 12,1611,599 3,19 13,17118,758,75 2,87 11,8711,58,58,5 3,03 12,47,5128,58,5 3,29 13,56128,758,75 3,37 13,86138,258,25 3,91 16
36 Artic 610101024,8 3,129 12,6Artic6119,59,5 3,22 13Art i c6,5119,259,25 3,10 12,56,511,599 3,24 1371199 3,01 12,261299 3,51 14,26138,58,5 4,03 16,2
37 Artic 7101010Årti c6111010Artic6129,59,571299
61399
38 Artic 6139,59,5Artic612101025.6 3,24 12,6 
3,59 H  
3,83 15 
3,62 14,1 
4,29 16,8
26.7 4,61 17,5 
4,20 16
a) Artic and/or Road Train unless specified.

ROAD DAMAGE OF 4 AXLE COMBINATIONS (34 - 37t total weight)
IN RELATION TO DRIVE AXLE WEIGHT
Drive axle weight ■