7 April 2012 Last updated at 07:42 ET

How fire under M1 exposed vulnerability of motorways

By Chris Summers BBC News

CCTV camera footage shows vehicles passing just metres from the flames

Six youths have been acquitted of starting a fire which closed the M1 for three days. But what became of a review of fire hazards under motorways and railways ordered by the transport secretary?

"There have been scrapyards under motorways for as long as there's been motorways," says Terry Mizon, whose yard under the M1 in Mill Hill, north London, was destroyed by fire in April 2011.

The blaze, which started in an alley between Mr Mizon's yard and a nearby skip business, caused the steel supports of the motorway to buckle and shut the M1 in both directions, affecting thousands of motorists and causing £4.5m worth of damage.

It caused massive traffic jams. Those affected included football fans travelling from Manchester, Bolton and Stoke-on-Trent for the FA Cup semi-finals at Wembley and amateur athletes attending the London Marathon that weekend.

The fire, coming on the weekend of the FA Cup semi finals at Wembley, caused chaos

But Det Sgt Gideon Mitchell, who worked on the investigation, said the CCTV footage of the fire - which shows cars and lorries driving only feet from where flames lick the side of the motorway - shows it could have been even worse.

"Someone could easily have died that night," he told the BBC.

Such was the furore that the then Transport Secretary Philip Hammond ordered a review of all major roads and railways in England to find out what fire hazards were stored under or near them.

The report was due to be compiled "within six weeks".

Mr Hammond, who has since become defence secretary, said at the time: "It is crucial that we learn the lessons from this hugely disruptive event and ensure that we minimise the risk of something similar happening again."

'Incredible' delay

A year later the report he commissioned has yet to see the light of day.

Defendants: clockwise from top left - Luke Matthews, Johno Johnson, Josh Lambe, Juan Durandt, Hannah Parker and Damien McQueen

Shadow transport secretary Maria Eagle told the BBC: "It's incredible that heading on for a year after the fire under the M1, the review into the lessons that need to be learned has still not been published."

She said she urged the government to widen the scope of the review in November, after seven people were killed in an accident on the M5 near Taunton, Somerset, amid claims that smoke from a nearby fireworks display could have contributed to the pile-up.

Avon and Somerset Police is still investigating the crash and inquests are pending but it emerged the organisers did not need a licence for the display.

Ms Eagle said: "The government must treat this issue with a much greater sense of urgency and report back to the Commons at the earliest opportunity."

Matthew Offord, the Conservative MP for Hendon in north London, tabled a question in Parliament earlier this year asking what had become of the report.

Roads Minister Mike Penning replied: "As a result of the fire the Highways Agency and Network Rail carried out audits to categorise potential sources of fire risk from third party activities at other critical locations beneath, or adjacent to, their respective networks.

Images on their mobile phones showed the youths posing in front of fires they had started

'Action Plan'

"The Highways Agency audit included recommendations that have been developed into an Action Plan, which is currently on programme for completion before the end of spring 2012."

A jury this week cleared six youths of arson in connection with the M1 fire. But they were among nine youngsters convicted of causing a series of other fires in the Edgware and Mill Hill areas will be sentenced on 4 May.

The M1 arson trial had heard the fire spread from the scrapyard to beneath the Deans Brook viaduct, which carries the M1.

It was so intense that 250 tonnes of steel scaffolding had to be erected beneath the bridge to prevent it collapsing. Repairs took six months and cost £4.5m.

Like the Buncefield fuel depot fire at Hemel Hempstead, Hertfordshire, which forced the closure of the M1 twice in 2005, the Mill Hill fire highlighted the vulnerability of major trunk roads.

The Buncefield fuel depot fire in 2005 was another reminder of the vulnerability of the road network

Many motorway flyovers have industrial estates underneath, while railways are arguably even more prone, because of the thousands of Victorian railway arches which have been leased out over the years.

A spokesman for the British Metal Recycling Association, which represents scrapyards, says: "The idea of banning such sites from operating under motorways and railways is unlikely to work - the list of businesses that do things which could go wrong at these sites is as long as your arm."

Mr Mizon says: "Are you going to ban anyone from having a gas bottle near a motorway? What about the hundreds of people who live in caravans under motorways and rely on gas bottles?"

Damage and repair to the M1

1. The fire, described as "unprecedented", began in an alley beneath the M1 motorway's Deans Brook viaduct in Mill Hill, north London, and spread to a nearby scrapyard, Apex Metals.

2. The heat was so intense some of the elevated road's concrete exploded, roads minister Mike Penning said. Some of the bridge's steel structure expanded, forcing concrete to fall away

3. Highways Agency workers erected 250 tonnes of steel pillars across the width of the carriageway to make the structure safe in the short term.

4. A firm of civil engineers, Jacksons, spent six months repairing the viaduct with occasional night time road closures. The total bill for the damage was £4.5m.