1991 No. 1526
ROAD TRAFFIC
The Road Vehicles (Construction and Use) (Amendment) (No. 1) Regulations 1991
Made 4th July 1991
Laid before Parliament 10th July 1991
Coming into force 1st November 1991

The Secretary of State for Transport, in exercise of the powers conferred by sections 41(1), (2) and (5) of the Road Traffic Act 1988 as read with section 43 of that Act and of all other enabling powers, and after consultation with organisations in accordance with section 195(2) of that Act, hereby makes the following Regulations—
1988 c. 52.

1 Citation and commencement
These Regulations may be cited as the Road Vehicles (Construction and Use) (Amendment) (No. 1) Regulations 1991 and shall come into force on 1st November 1991.

2 Preliminary
1 The Road Vehicles (Construction and Use) Regulations 1986 shall be further amended in accordance with the provisions of these Regulations.
S.I.1986/1078 ; relevant amendments are S.I.1988/1524 and 1990/1131.
2 The Secretary of State is satisfied that—
(a) it is requisite that the provisions of regulations 3, 4 and 5 shall apply as from 1st November 1991 to vehicles registered under the Vehicles (Excise) Act 1971 before the expiration of one year from the making of these Regulations; and
1971 c. 10.
(b) notwithstanding that the said provisions will then apply to those vehicles, no undue hardship or inconvenience will be caused thereby.

Amendments to provisions concerning composite trailers
3 For the definition of “converter dolly” in the Table in regulation 3(2) there shall be substituted—

“(a) a trailer which is—
(i) equipped with 2 or more wheels,
(ii) designed to be used in combination with a semi-trailer without any part of the weight of the semi-trailer being borne by the drawing vehicle, and
(iii) not itself a part either of the semi-trailer or the drawing vehicle when being so used; or
(b) a trailer which is—
(i) equipped with 2 or more wheels;
(ii) designed to be used in combination with a semi-trailer with part of the weight of the semi-trailer being borne by the drawing vehicle;
(iii) not itself a part either of the semi-trailer or the drawing vehicle when being so used; and
(iv) used solely for the purposes of agriculture, horticulture or forestry, or for any two or for all of those purposes.”

4 In Part II of Schedule 8, at the end of note (b) there be added the words “manufactured before lst February 1992”.

5 Amendments to regulation 61 (emission of smoke, vapour, gases, oily substances, etc.)
1 Regulation 61 shall be amended as follows—
2 In paragraph (1), after the word “constructed” there shall be inserted the words “and maintained”.
3 After paragraph (3A) there shall be inserted the following paragraphs—

“3B Instead of complying with paragraph (1) a vehicle may comply with a relevant instrument.
3C Instead of complying with such provisions of items 1, 2 and 3 in Table I as apply to it, a vehicle may at the time of its first use comply with a relevant instrument.”

.
4 In paragraph (4), for the words from the beginning to “comply” there shall be substituted the words “For the purposes of paragraphs (3B) and (3C), a reference to a vehicle complying with a relevant instrument is a reference to a vehicle complying”.
5 After paragraph (10) there shall be inserted the following paragraphs—

“10A Without prejudice to paragraphs (1) and (7) no person shall use, or cause or permit to be used on a road, a vehicle first used on or after the I August 1975 and propelled by a four-stroke spark ignition engine, unless the vehicle is in such a condition that, when the engine is idling—
(a) the carbon monoxide content of the exhaust emissions from the engine does not exceed—
(i) in the case of a vehicle first used on or after 1 August 1983, 4.5% or
(ii) in any other case, 6%;
of the total exhaust emissions from the engine by volume; and
(b) the hydrocarbon content of those emissions does not exceed 0. 12% of the total exhaust emissions from the engine by volume.
10B Paragraph (10A) does not apply to—
(a) a vehicle if at the date that the engine was manufactured, that engine was incapable of meeting the requirements specified in that paragraph;
(b) a vehicle being driven to a place where it is to undergo repairs;
(c) a vehicle which was constructed or assembled by a person not ordinarily engaged in the business of manufacturing motor vehicles of that description;
(d) an exempt vehicle within the meaning given by paragraph (12)(a) above;
(e) a goods vehicle with a maximum gross weight exceeding 3,500 kg;
(f) engineering plant, an industrial tractor, or a works truck; or
(g) a Class V or Class VI vehicle within the meaning of the Motor Vehicles (Tests) Regulations 1981.
S.I.1981/1694 ; relevant amending instruments are 1984/1126 and 1988/1894.”

Signed by authority of the Secretary of State for Transport
Christopher Chope Parliamentary Under Secretary of State, Department of Transport 4th July 1991

(This note is not part of the Regulations)
These Regulations further amend the Road Vehicles (Construction and Use) Regulations 1986. They make provision for converter dollies used for agricultural and similar purposes. They also amend the provisions which relate to exhaust emissions.

Converter dollies
A converter dolly is a trailer which can be used in combination with a semi-trailer so that the combination of the two operate as a single draw bar trailer.
By virtue of regulation 3(11) of the 1986 Regulations, a combination of the two trailers is treated as one trailer for the following purposes:
(a) regulation 7 (length),
(b) certain provisions in regulation 75 (maximum permitted laden weight of a vehicle),
(c) regulation 76 (maximum permitted laden weight of a vehicle and trailer other than an articulated vehicle),
(d) certain provisions in regulation 78 (maximum permitted wheel and axle weights), and
(e) regulation 83 (number of trailers).
The exemptions apply only where one of the vehicles in the combination is a “converter dolly” as defined in the Table in regulation 3(2) of the 1986 Regulations. In order to come within the definition as originally drafted a trailer had to be so designed that no part of the weight of a semi-trailer used in combination with it was borne by the towing vehicle.
Part 11 of Schedule 8 of the 1986 Regulations sets out the information which has to be contained in plates fitted to trailers pursuant to regulation 66. In the case of trailers which impose some weight on the drawing vehicle, the information on the plate has to include the maximum load imposed on the drawing vehicle. Converter dollies were, however, exempt under these provisions as originally drafted.
These Regulations amend the definition of “converter dolly” so that a trailer can come within the definition even though part of the weight of the semi-trailer is borne by the towing vehicle, provided the trailer in question is used solely for the purposes of agriculture, horticulture or forestry.
As a consequence, Part 11 of Schedule 8 is amended so that plates fitted under regulation 66 to converter dollies manufactured after 1st February 1992 which impose some load on the drawing vehicle have to state the maximum load imposed on the drawing vehicle.
The opportunity has been taken to make some minor drafting improvements to the definition as it applies to trailers not used for the purposes of agriculture, etc.

Exhaust emissions
Regulation 61 previously contained a provision requiring vehicles to be constructed so as not to emit any avoidable smoke or avoidable visible vapour. This provision is amended so that vehicles not only have to be constructed but also maintained so as not to emit any avoidable smoke or avoidable visible vapour.
A new paragraph (10A) is added to regulation 61 which makes it unlawful for a vehicle with a 4 stroke spark ignition engine to be used if it is in such a condition that, when the engine is idling, the carbon monoxide and hydrocarbon content of the exhaust emissions exceeds specified limits. The limit, in the case of the carbon monoxide content, is 4.5% if the vehicle was first used on or after 1st August 1983 or 6% in any other case. The limit in the case of hydrocarbon content is 0.12%. The provision applies only to vehicles first used on or after 1 August 1975. Exemptions from the new paragraph (10A) are contained in a new paragraph 10(B).