Richard Caddock, 38, from Bexleyheath, London, was talking on a mobile phone and could not hear the approaching truck above the noise of nearby motorway traffic, when he was hit from behind on 8 April 2008.

Costain faced charges for failing to ensure adequate precautions were in place to separate the movements of people and vehicles.

Maidstone Crown Court heard that Caddock, of Bexleyheath, London, had left a parked van and was walking northbound along a section of the central reservation closed off as part of a £65m scheme to ease congestion between junctions 1b to 3.

As he talked on the phone, a tipper lorry delivering crushed stone entered the same section and reversed northbound. Craddock had walked approximately 30 metres when the truck hit him.

The surveyor sustained multiple injuries as a result of being run over by the eight wheel vehicle and was pronounced dead at the scene.

After the hearing HSE Inspector Melvyn Stancliffe said: “This was a terrible tragedy that could easily have been avoided had Costain Limited implemented basic safety precautions.

“Mr Caddock may have been distracted on the phone, but the drone of nearby traffic was such that he would have struggled to hear the reversing alarm on the lorry regardless. Quite simply the two should never have been allowed to be in the same place at the same time.

“The movement of people and vehicles on construction sites requires careful planning and effective control. It must be considered a critical part of transport management. This case highlights that a failure to be in control can have devastating consequences.”

Costain pleaded guilty to safety breaches and was fined £250,000 with £45,000 in costs.