Loon-Plage english summary
At about 21:20 9 June 2014, a coach travelling on National Trunk Road No. 316 going towards Gravelines with 51 passengers on board overturned on its right side at the exit of a roundabout in the municipality of Loon-Plage in the Nord department.
This accident cost the life of one passenger in the coach. 10 of its other occupants were injured, of which four were hospitalised for more than 24 hours.
The direct cause of the accident was the excessive speed of the coach as it entered the roundabout, which caused it to overturn as it went through.
This excessive speed was the consequence of manoeuvres made by the driver of this coach, who was unable to slow it down using the manual controls of the speed governor and the speed retarder or by pressing the pedal to activate the main air brake.
The reasons why the coach involved could not be slowed down using the controls mentioned above could not be determined with certainty. The most likely reason is that its driver was impaired by an unfortunate and involuntary action which held in or re-engaged the speed governor.
Two factors played a role in this situation :
- the ergonomics of the manual speed governor and retarder controls which are grouped on one and the same multi-function lever, where there is a risk of confusion between the safety functions and the driving aids when activated ;
- incomplete training of the drivers of passenger service vehicles in the conditions for safe use of the driving aids, particularly during obligatory vocational training.
In view of these factors, BEA-TT made a recommendation concerning the ergonomics of the manual controls of speed retarders and speed governors.
In addition, without formalising the recommendation, BEA-TT reiterated its call for the Directorate General of Infrastructure, Transport and the Sea (DGITM) to call on the bodies responsible for the initial and in-service training of goods and passenger road vehicle drivers to include raising the awareness of these drivers to good driving practices on vehicles equipped with speed retarders and speed governors so as to meet essential safety requirements in particular in their obligatory training.