Coulombiers english summary

This report presents the analyses and conclusions of the technical investigation done at the request of the Ministry of Public Works, Transport, Housing, Tourism and the Sea, on the November 5th, 2002 pile-up which occurred on the A 10 motorway in Coulombiers. The accident left 8 dead and 40 injured, 6 seriously.
The technical investigation’s objectives were to piece together the circumstances surrounding the accident as well as its unfolding, to identify determining causes and factors, and then draft all useful preventive recommendations to avoid a repeat event.

A first interim report, dated December 10th, 2002, had as a priority, to determine what reinforced monitoring measures were to be implement on that specific section of the A 10 motorway where two accidents had happened in 2002 in very similar conditions. The following stages involved deeper expert analyses and investigations of the damaged vehicles, weather conditions and possible origin of smoke.
The accident occurred when a particularly thick blanket of fog and smoke arose, reducing local visibility to a few meters, in contrast with thinner fog upstream and downstream from the accident site.
The accident occurred in the south to north bound lanes, where the fog density caught drivers unawares. In the north to south bound lanes, an accident which could have proven just as serious was avoided most likely thanks to the protections set up by one of the highway staff, also reinforced by an alerting messaged quickly put on the traffic information display system close by.

Among the various factors inherent to driver behaviour and compliance with regulations, excessive speed plays a major role. Cars and heavy goods vehicles were both driving close to the maximum speed authorised by clear weather, which was inappropriate since there were patches of thick fog. Besides, two heavy goods vehicles and several cars had apparently not slowed down particularly when entering the fogy area where the accident occurred.
Adapting one’s behaviour and speed to foggy weather conditions must therefore become a notion reinforced during both initial and refresher training courses for heavy goods vehicle drivers. In addition, in view of the high number of drivers travelling on business and involved in the accident, this reminder should also be relayed through company road traffic hazards prevention plans. This should also be conveyed in all the communication and information campaigns targeting the public in general.

Concerning the meteorological elements, a study was done by the French National Weather Bureau « Météo-France » using digital simulation modelling, to determine whether in either of the 2002 accidents, smoke produced by the Coulombiers charcoal factory could have been involved. The conclusions point to a probable interference during the January 29th accident and a possible yet low interference in the November 5th pile-up. Nevertheless, proper use of the smoke incinerator installed at the plant should reduce such risks from now on.

As far as operating and monitoring the motorway, recommendations to the ASF Concessionaire focus on reinforcement of equipment and strengthening of procedures to alert drivers quickly in case of an emergency and particularly in case of thick fog : patrolling, traffic information display systems, a dedicated radio channel and the installation of flashing lights or strobe lights on emergency call boxes. This last point (flashing lights on emergency call boxes) should be submitted at national level as a technical recommendation.
ASF, the motorway Concessionaire, should intensify its monitoring activities along the motorway section where the accident occurred because the coincidence of two similar serious accidents both happening in 2002 amply justifies the fear that recurring local interferences could produce thick fog or smoke.