A FULL-scale review of the amount of time roads are closed after serious accidents has been called for by the RAC Foundation.

Such closures account for an estimated quarter of all congestion and cost the country more than £5 billion a year, the foundation said.

It added that although it was vital police properly investigated fatal accidents, this had to be set against a requirement to keep traffic moving.

The foundation said that in the last three months of 2008, there were 86 closures of English motorways lasting more than three hours. Yet for the whole year across Britain there were only 136 fatal motorway crashes.

The foundation published a report from former Whitehall transport expert Irving Yass which found: :: The police's 2007 road deaths investigation manual was based on the principle that all fatal collisions should be investigated as "unlawful killings" until the contrary is proved; :: There are currently no national statistics on how many detailed accident investigations take place, nor how many prosecutions result from them; :: There does not appear to be a standard practice in deciding when to deploy specialist investigation teams to non-fatal accidents; :: A snapshot of four police forces - London, Essex, Humberside and Surrey - indicates the number of investigations is around three times the number of actual fatalities.

The report recommended that police authorities should maintain 24-hour cover by specialist accident investigation teams and accidents should be investigated by the nearest team even if it is from a neighbouring force.

Also, thought should be given to removing the investigation role from individual constabularies and creating a national unit.

Commenting on the report, RAC Foundation director Professor Stephen Glaister said: "The investigation of road accidents is a very sensitive area. It is vital for the families of victims to know what happened and for road users who break the law to be punished.

"The police and other agencies are well aware of competing priorities when it comes to dealing with road accidents, but this report suggests a review of the processes involved would be timely."

He went on: "Closed roads can cause major congestion, huge losses to the economy and in the worst cases even more accidents. The right balance has to be found between delivering justice and keeping the country moving.

"As the population increases and we come out of recession, traffic will grow and road closures - for whatever reason - will increasingly impact on the way we get about."

Chief Constable Mick Giannasi, the Association of Chief Police Officers' (Acpo) lead for road policing, said the RAC Foundation report would be considered and the author had identified "the dilemma which police forces face on a daily basis".

Mr Giannasi said a thorough and detailed investigation should be carried out when people were killed or suffered life-changing injuries as a result of a road accident for the sake of victims and their families and to ensure lessons were learned.

"In many serious and fatal collisions, there is an element of criminal liability and the police have a duty to bring those responsible to justice. Society and the families of those involved would accept nothing less," he added.

"Against that background, the police service is acutely aware of the cost and disruption caused by road closures and the impact that this has on individuals and communities. As such, police officers do not take the decision to close the road lightly."

Mr Giannasi, who is Chief Constable of Gwent Police, said forces share good practice and Acpo works hard to ensure that the approach is as consistent as possible.

"However, roads policing in London is vastly different to roads policing, for example, in Dyfed Powys and a one-size-fits-all solution is neither realistic nor desirable," he said.

"For this reason I do not believe that a fundamental review of roads policing is necessary."

Mr Giannasi said the Road Death Investigation Manual provided clear guidelines for forces.

"It is regularly reviewed to ensure that it remains current and another review has recently been instigated."

He added that, during the past two years, the police and the Highways Agency had regularly been questioned about motorway closures in particular and a number of steps had been put in place to reduce the length of time traffic flow was disrupted.