FOUR-LANE motorways are more dangerous than their three-lane counterparts under some traffic conditions, documents released by the Highways Agency have revealed.
'At low flows for a four-lane motorway (less than 120,000 vehicles per day), four-lane motorways have a poorer safety performance than three-lane motorways, ' stated the Agency, in response to a Freedom of Information Act request on the safety of four-lane highways.
The Agency added that the overall accident rate for a fourlane motorway is marginally higher than that for its threelane equivalent, although 'fourlane motorways have significantly lower rates of fatal and serious injuries than two- and three-lane motorways across the range of flows'.
The figures are drawn from an unpublished study carried out by transport research body TRL in 2002.
The Agency played down the importance of TRL's figures.
'The Highways Agency routinely monitors the safety performance of all our roads and takes the necessary action to reduce accidents, ' said a spokesman.
'We have also approved R&D projects to investigate and report on international best practice for traffic signing and traffic management for roadworks on 'wide' motorways this year.
We are not aware of any other specifi c additional research into the safety of four-lane or wide motorways, ' he added.