Your article incorrectly claims the Highways Agency is putting lives at risk by failing to adopt fire suppression systems for the A3 Hindhead tunnel (News last week).
The Hindhead tunnel has been designed with twin bores, a standard height gauge and cross passage escape routes at 100m intervals. It will carry relatively low traffic flows compared to the A86 single bore tunnel in Paris, which was used as a comparison.
The likelihood and consequences of a fire in the A86 single bore tunnel in Paris are therefore very different to Hindhead.
The cost benefit analysis of installing a fire suppression system at Hindhead shows it cannot be justified when comparing the safety risks, disruption to traffic and cost of repair with the whole life cost of the system, including maintenance and renewal.
The costs of providing a suppression system are over three times the potential safety benefits and fall into the 'grossly disproportionate' category.
Most of the benefits come from 'asset protection'.
We recognise that the development and research into suppression systems in tunnels is still at an early stage and costs may well reduce in the future.
We are therefore providing key support infrastructure to minimise the cost of fitting a system at a later stage.
Surrey Fire & Rescue supports our commitment to keep the matter under review.
Paul Arnold, Project Team Leader, Major projects, Highways Agency, Federated House, London Road, Dorking RH4 1SZ