§ Mr. Clifton-BrownTo ask the Secretary of State for the Environment, Transport and the Regions (1) what decibel projections were modelled for the proposed A417/A419 DBFO road; what decibel readings have been taken by the Department, or other agencies, on the road(a) before and (b) after it was constructed; at which points along the road the readings were taken; and whether any of these readings are above the Department's decibel mean; [35346]
- (2) what were the costs of surfacing an average mile of the A419/A417 DBFO road in (a) HRA, (b) SMA and (c) concrete; [35348]
- (3) what critical noise modelling has been undertaken in respect of the A419/A417 DBFO road; and what the results are; [35347]
- (4) which sections of the A419/A417 DBFO road are surfaced with (a) hot rolled asphalt, (b) stone mastic asphalt and (c) concrete; how many miles in total of the A419/A417 DBFO are surfaced with each; and what reasons underlay the use of different surfaces; [35345]
- (5) what would be the cost of roadsurfacing all the concrete surfaces on the A419/A417 DBFO road between Latton and Nettleton Bottom with hot rolled asphalt. [35349]
§ Dr. StrangI have asked the Chief Executive of the Highways Agency, Mr. Lawrie Haynes, to write to the hon. Member.
151WLetter from Lawrie Haynes to Mr. Geoffrey Clinton-Brown, dated 25 March 1998:
The Minister for Transport, Dr. Gavin Strang, has asked me to reply to your recent Parliamentary Questions about the new A417/A419 DBFO scheme.About 15 miles of the road between the M4 and Marston Meysey and between Cowley Roundabout and the M5 are surfaced with Hot Rolled Asphalt (HRA). The sections surfaced with Stone Mastic Asphalt (SMA) total about 7 miles and are at Marston Meysey, the Churn Valley Viaduct and from Stratton to Cowley Roundabout. About 8.2 miles of the road from Latton Village to Quarry Junction have a concrete surface, apart from section across the Churn Valley Viaduct.Under the terms of the contract, the choice of road carriageway materials was entirely a matter for the contractor.Noise predictions were calculated in accordance with "Calculation of Road Traffic Noise" (CRTN), a copy of which can be seen in the House of Commons Library. I am arranging for a copy of the noise report that was prepared for this scheme under CRTN to be sent to you direct. We are checking the road traffic noise calculations to ensure that the correct assessments have been made. Noise readings, which use a different unit of noise measurement, were taken at eighteen Control Stations along the route to record the ambient noise levels before work started and to monitor the level of construction noise. Measurements are also being taken now at the same control stations.Because this is a Design Build Finance Operate contract we do not have exact details of the costs incurred in laying the road surfaces used. However the Department's Agent estimates that the cost of constructing the full depth of pavement with different surfacings on an average mile of the road were
£ a. HRA 935,000 per mile b. SMA 965,000 per mile c. Concrete 645,000 per mile These estimates do not take account of any consequential changes in earthwork quantities due to the different pavement thicknesses.There are no plans to resurface the concrete section with (HRA) and in any event there may be difficulties in doing so because the thickness of the (HRA) surfacing required would affect the drainage design, the height of the safety barriers and the headroom at bridges; major work could be required to overcome the problems.If the concrete carriageway were to be overloaded with a thin surfacing such as SMA the estimated cost would be £1.4 million (excluding VAT, any preliminaries, insurances, drainage and maintenance costs).