Characteristics and Causes of Traffic Accidents on Freeway Upgrade Sections

Based on traffic accident statistics during 2006 to July 2010 of East Lushan segment of Nanjing-Hangzhou Freeway,the characteristics of traffic accident on upgrade sections were analyzed from the view of accident site,accident period,accident form and accident vehicle type.The study shows that the freeway upgrade sections are more prone to traffic accidents than the downhill and the other sections.Accident always occurs in the middle and rear part of straight slope section and vertical curve segment.The accident forms are mainly rear-end,hitting guardrail or fixtures.It is worth mentioning that a large proportion of major traffic accidents are also rear-end.Accident rate and severity of accidents of the night are larger than those of the day.It is prone to have accident especially early in the morning from 2:00 to 6:00.Large trucks and small passenger cars are the main bodies of traffic accidents on freeway upgrade sections.The accident causes are fatigue driving,significant discreteness of speed and complicated traffic composition.