An overturned lorry looms over the wreckage of a Ford Fiesta crushed under the weight of the HGV's load.

Further up the hard shoulder a tanker has broken down and its load has spilled on the carriageway.

The only sound comes from a minibus of students shocked and distraught at the carnage that is unfolding before them.

Before long, Highways Agency traffic officers arrive at the scene, responding to an emergency call made from a roadside telephone.

See a slideshow of the event

It later emerges the lorry driver managed to break free from the wreckage and raise the alarm.

Fire crews arrive next, working their way through the standing traffic with police and ambulance crews on their tail.

The teams join forces to assess the risks and get the passengers to safety while working to clear the motorway.

The passengers in the minibus are becoming increasingly distressed and it is feared they may try to cross the carriageway.

Ambulance crews calm them before carrying one casualty off on a spinal board and leading the others to safety.

A passenger in a neighbouring car has sustained head injuries and is also lead to an ambulance.

Meanwhile, fire crews build towers under the truck to secure it before recovery vehicles drag the Fiesta out from the wreckage.

Crushed cars are winched to the back of the breakdown trucks and taken away. The tanker was carrying chemicals and a substance is sprayed on the road surface to neutralise it.

Accident investigators set to work, using hi-tech satellite equipment to asses what has happened.

Throughout the incident the motorway has been closed in both directions to allow emergency access.

Highways Agency traffic officers have been working to alert radio stations and arrange diversions to limit the build-up of standing traffic.

Finally, ropes are attached to the overturned truck and it is raised to safety.

Throughout the exercise teams work together to secure the safety of those involved and to clear the motorway as quickly as possible. The whole operation is over in just an hour and a half.

Fortunately this is a training exercise to drill the response to major motorway incidents, and the casualties are actors from Southport College.

North West Traffic Officer Service (NWTOS) team manager Shane Harrington said: "Our on-road and control room traffic officers have dealt with many serious real-life incidents and we have both 'hot' and 'cold' debrief systems in place with our partners such as the police so we can learn lessons from each of them.

"However, the idea of Exercise Valentine is to allow managers of the emergency services and the traffic officer service to take a step back and observe how colleagues respond to a serious incident without getting involved."

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