§ Mr. Mike O'BrienTo ask the Secretary of State for Transport (1) what studies his Department has undertaken into the use of porous asphalt in the United Kingdom;
(2) on how many occasions in the last five years where commercial vehicles are likely to use a motorway, at the rate of over 4,000 vehicles per lane per day, permission has been given for the use of porous asphalt in the construction of the road;
(3) if he will set out the criteria by which decisions have been made to use porous asphalt on motorways, or other developments, in the United Kingdom in the last five years;
(4) if he will list the developments where porous asphalt was used on motorways and trunk roads in the last 10 years;
(5) what EC directives or regulations relate to the use of porous asphalt on motorways or trunk roads.
§ Mr. KeyThese five questions concerning the use of porous asphalt relate to operational matters of the Highways Agency. I have asked the chief executive, Mr. Lawrie Haynes, to write to the hon. Member.
Letter from Lawrie Haynes to Mr. Mike O'Brien, dated 20 May 1994: 159W
The Minister for Roads and Traffic, Mr. Robert Key, has asked me to write to you in response to the five questions you asked relating to the use of porous asphalt.The Department, in conjunction with TRL and industry, has been investigating the design and production of porous asphalt surfacings for many years including taking account of developments abroad. This work included laboratory tests as well as longer term road trials to optimise the performance of porous asphalt. These trials included sites on the A38 at Burton on Trent, the M1 south of Leeds and the M6 north of Junction 18 in Cheshire.The successful outcome of these trials led to the Minister's announcement on 28 July 1992, that porous asphalt surfacing could be used on schemes in future where the conditions were suitable, benefits outweigh the higher cost and the needs for more expensive winter maintenance and more frequent resurfacing. Porous asphalt is not suitable for use on all roads. The criteria on which decisions are based for adopting porous asphalt surfacings are set out in Volume 7 of the Department's Design Manual for Roads and Bridges at document HD27/94 entitled "Pavement Construction Methods" and published in January 1994. These advise it is not used where traffic exceeds 4,000 commercial vehicles per lane per day.Use of porous asphalt surfacing has been approved for a number of schemes within criteria laid down. Additionally, use has been approved on two lengths of the M25 where the traffic exceeds 4,000 commercial vehicles per lane per day in order to gain experience of the more durable mixtures at higher traffic levels.Apart from the trial applications mentioned above, two other projects are under construction where porous asphalt is due to be laid. The schemes are:
- A5 Fazely-Two Gates-Wilnecote BP
- A50 Blyth Bridge-Queensway Improvement
The above information relates purely to roads in England. Porous asphalt has also been laid by local authorities on roads for which they are responsible.Use of porous asphalt, as with any other surfacing material, is subject to EC directives and regulations on safety. Additionally specifiers are bound within the Public Procurement Directive. In accordance with this requirement the Technical guidance, as given in document HD27/94, was notified to the EC under the terms of the Notification Directive.