Discriminant Analysis of Factors Affecting Traffic Accident Severity During Daytime and Nighttime

판별분석을 활용한 주·야간 고속도로 교통사고 영향요인 비교연구

Kim, Kyoungtae;Lee, Soobeom;Choi, Jihye;Park, Sinae;Seo, Geumyeol

  • Received : 2016.03.30
  • Accepted : 2016.05.20
  • Published : 2016.06.15


PURPOSES : Low visibility caused by dark surroundings at nighttime affects the likelihood of accidents, and various efforts, such as installing road safety facilities, have been made to reduce accidents at night. Despite these efforts, the nighttime severity index (SI) in Korea was higher than the daytime SI during 2011-2014. This study determined the factors affecting daytime and nighttime accident severity through a discriminant analysis. METHODS : Discriminant analysis. RESULTS : First, drowsiness, lack of attention, and lighting facilities affected both daytime and nighttime accident severity. Accidents were found to be caused by a low ability to recognize the driving conditions and a low obstacle avoidance capability. Second, road conditions and speeding affected only the daytime accident severity. Third, failure to maintain a safe distance significantly affected daytime accident severity and nonsignificantly affected nighttime accident severity. The majority of such accidents were caused by rear-end collisions of vehicles driving in the same direction; given the low relative speed difference in such cases, the shock imparted by the accidents was minimal. CONCLUSIONS : Accidents caused by a failure to maintain a safe distance has lower severity than do accidents caused by other factors.


discriminant function;accident severity;factor of accident;accident at daytime;accident at nighttime


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