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Noise regs not enforceable,

24th May 1968, Page 35
24th May 1968
Page 35
Page 35, 24th May 1968 — Noise regs not enforceable,
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Which of the following most accurately describes the problem?

says police chief by Tony Wilding

• Regulations defining noise-level limits come into effect on July 1 and could mean trouble for many operators. On a simulated roadside check organised by Dawe Instruments Ltd., on A20 outside Brands Hatch racing circuit on Monday, a number of trucks were very close to the 92 decibel limit and one which did not sound unduly noisy exceeded it by a fair margin.

Representation by operators' associations for raising the limit have been unsuccessful. But the demonstrations showed that in practice there may riot be such a lot to worry about. Checks were made according to the regulations with the microphone part of the equipment in the open, as it has to be to meet the testing-procedure requirements. And drivers of noisy vehicles will probably catch on to the fact that, when they see a microphone set up by the road, lifting off the accelerator and dabbing the clutch out, or cutting the noise in any other way for 25ft on either side of the mike, will put their "reading" in the clear.

There is another factor. At a discussion period after the demonstrations there was much criticism of the regulations by senior police officers present, who clearly held the view that the regulations were unenforceable. Mr. Alec Muir, chief constable of Co. Durham, went so far as to say that they were "absolutely unenforceable"—he said also that he believed his views were held by every other chief constable in the country. Others that I spoke to said that they had no intention of buying meters to check vehicle noise at the roadside.

Most of the criticism was that the meters were only capable of giving accurate readings for a specific vehicle in an open location where vehicle noise was far less of a problem than in built-up areas. Others said that vehicles made the greatest noise when accelerating to overtake and with other vehicles present a proper reading could not be taken.

These criticisms were all concerned with the intention to make roadside checks. Many experts in the "noise field" will argue strongly against the feasibility of these checks and Stress that the only realistic method is to set up test facilities giving controlled conditions away from other traffic.

There is agreement with the regulations relating to vehicles built from April 1 1970 and stipulating the manufacturing criteria, as this will tackle the problem at source. If the figures in the regulations had been used as standards from five years ago, when the prospect of noise regulations became evident, there would be little need for road-side checks now, as most too-noisy vehicles would be over the level through a faulty part such as a silencer.

A strong case has been made to increase the in-use figure of 92 decibels to 95 and this has been turned down. It is hard to see with what justification, for the regulations have the effect of requiring existing vehicles to meet a noise level on July 1 which will only have to be met by new vehicles in April 1970. They quote 92 decibels for the former and 89 for the latter but the three-decibel difference is equal to the three-decibel allowance that the MoT says is incorporated in the in-use figure to take account of background noise on roadside checks; new-vehicle checks will be made under controlled conditions.

No satisfactory answer as to the reason for this was obtained from a senior engineer of the MoT on the "panel" during the discussion session. Agreements at an -international level" were referred to, but this was not the point. The question was and still is: "Why do operators have to meet a requirement this July which in effect is identical to that which manufacturers will have to comply with almost two years later?" A vehicle-manufacturers' representative on the panel said that his vehicles would meet the standard by July, but even this does not absolve the industry from the criticism of producing some models which it must have known would exceed future legal noise-level limits which were defined when they were built.

Accuracy of meters developed for the tests are not in doubt, but scepticism exists on the question of accuracy in taking readings. The noise level reached by a vehicle is indicated by a needle on a dial and the maximum position is held only momentarily. Demonstrations using six instruments with their microphones set close together showed discrepancies of up to two decibels between readings for the same vehicle. When it is realized that this represents a 20 per cent variation in the level of noise, and can mean the difference between a conviction and "no action", the regulations are seen in a truer perspective.

What is truly surprising is that, with the police saying that the regulations are unenforceable, with leading UK experts on noise research saying that roadside checks are completely impractical and with the industry pleading for some leeway in the in-use and new-vehicle figures, the Ministry of Transport should go blithely ahead with them. Yet a Ministry spokesman is reported as saying that "the MoT has conducted tests with noise meters for many months and is satisfied that the regulations are both workable and enforceable."

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Organisations: Ministry of Transport
Locations: Durham

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