§ Mr. AmessTo ask the Secretary of State for the Environment, Transport and the Regions what the specifications for use are of(a) corrugated steel crash barriers and (b) concrete crash barriers on (i) motorways and (ii) trunk roads; and what criteria were used in determining the specifications. [154472]
§ Mr. HillI have asked the Chief Executive of the Highways Agency, Tim Matthews, to write to the hon. Member.
Letter from John Kerman to Mr. David Amess, dated 26 March 2001:
CRASH BARRIERS
The Transport Minister, Keith Hill, has asked Tim Matthews, Chief Executive of the Highways Agency to reply to your recent Parliamentary question concerning specifications and criteria for crash barriers. I am replying in the absence of Tim Matthews.
The specifications for corrugated steel and concrete crash barriers are given in the Manual of Contract Documents for Highway Works, Volume 1 Specification for Highway Works. Additional information is given in the Manual of Contract Documents for Highway Works, Volume 3 Highway Construction Details (Section 2). No distinction is made between the use of steel and concrete for normal containment on motorways and trunk roads.
You have also asked what criteria are used in determining their specification. There are two steps used to determine the criteria for the use of safety barriers.
The first step is to consider what level of protection is appropriate for the specific conditions on the road concerned. In most situations this would require a normal containment safety harrier, defined as being able to contain and safely redirect a 1.5 tonne car travelling at 110 kph (70 mph) and impacting at an angle of 20°. This is equivalent to an impact from a family size saloon travelling at the maximum legal speed on a motorway under normal conditions. This is an internationally recognised standard used on many motorways and A class roads throughout Europe.
The second step is to consider the need to refine the general specification to take into account any special roadside features or conditions that might: limit the amount of deflection provided by the barrier; require a higher level of protection; or involve environmental and aesthetic considerations. Guidance on such matters is given in the Highways Agency's design standard TD 19/85 "Safety fences and barriers".
Copies of the documents referred to are held in the House of Commons library.
If you would like any further information about this matter, please contact Brian Hill, in Room 4/30, St Christopher House, Southwark Street, London, SE1 OTE (telephone 020 7921 4936).