The majority of Thai people believe that an accident is the subject of wide, but part of the accidents are caused by not having knowledge of driving and neglect to try hard to find the true knowledge, but in fact most of the laeosahetu of the actual accident caused by "negligence of a person driving a" defect of road construction to make a road curve curved elbow or allowances is not cascade to the turning direction of the vehicle, or as a road hump caused the fatal accident.