THE only way to prevent a repeat of a horrific motorway crash in which seven people died would be fog detection devices and signs warning of possible reduced visibility, the West Somerset Coroner claims.

Michael Rose has written to several organisations expressing concern that proposals following the accident just north of Junction 25 of the M5 involving 34 vehicles which also left 51 people injured on November 4, 2011 do not go far enough.

At a recent hearing, Mr Rose said the pile-up was caused by reduced visibility from thick fog – he said smoke from a nearby fireworks display at Taunton Rugby Club was not to blame, although it could have mixed with fog and made the situation worse.

In a report released last week, he said Highways Agency proposals for detection automatic signalling between Junctions 23 and 25 would pick up on vehicles suddenly slowing down due to a hazard and alert other motorists.

But he added: “These proposals, whilst possibly preventing further vehicles entering an accident scene or a large area of reduced visibility, would not have prevented the initial incident and this can only be achieved by the erection of fog detection devices and greater use of overhead gantries displaying signs warning of events that may cause reduced visibility.”

Mr Rose recommends risk assessments before firework displays, while lookouts should be posted to warn of any smoke or fog approaching a major road or railway line, and displays should be stopped if an emergency arises.

He also wants consideration to be given to requiring firers and their assistants to be licensed for periods of five years and for local licensing authorities to advise anybody holding displays of potential risks.

Mr Rose expressed concerns that, despite the number of deaths and injuries at the M5 tragedy, the stretch of road is not deemed to need “special consideration”.

He said: “As the criterion for deploying road safety equipment is six personal injury collisions in three years, the present incident would not qualify for special consideration.”