title: Risk factors affecting the severity of traffic accidents at Shanghai river-crossing tunnel.
abstract: OBJECTIVE
  With increasing traffic volume and urban development, increasing numbers of underground tunnels have been constructed to relieve conflict between strained land and heavy traffic. However, as more long tunnels are constructed, tunnel traffic safety is becoming increasingly serious. Thus, it is necessary to acquire their implications and impacts. This study examined 4,539 traffic accidents that have occurred in 14 Shanghai river-crossing tunnels for the period 2011-2012 and analyze the correlation between potential factors and accident injury severity.
  
  
  METHODS
  An ordered logit model was developed to examine the correlation between potential factors and accident injury severity.
  
  
  RESULTS
  Results show that increased injury severity is associated with male drivers, drivers aged 65 years or older, accident time from midnight to dawn, weekends, wet road surface, goods vehicles, 3 or more vehicles, 4 or more lanes, middle speed limits (50-79 km/h), zone 3, extra-long tunnels (over 3,000 m), and maximum longitudinal gradient.
  
  
  CONCLUSIONS
  This article aims to provide useful information for engineers to develop interventions and countermeasures to improve tunnel safety in China.
authors.affiliation: a Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji University , Shanghai , P.R. China.|b Jiangsu Province Collaborative Innovation Center for Modern Urban Traffic Technologies, Southeast University , Nanjing , P.R. China.
authors.forename: Jian John
authors.initials: JJ
authors.lastname: Lu
authors.affiliation: c School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University , Shanghai , P.R. China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Xing
authors.affiliation: a Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji University , Shanghai , P.R. China.|b Jiangsu Province Collaborative Innovation Center for Modern Urban Traffic Technologies, Southeast University , Nanjing , P.R. China.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.affiliation: c School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University , Shanghai , P.R. China.
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Cai
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D000328:Adult; D000368:Aged; D002681:China; D004779:Environment Design; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012449:Safety; D015599:Trauma Severity Indices; D014947:Wounds and Injuries / Q000453:epidemiology*; D055815:Young Adult
keywords: accident injury severity; ordered logit model; risk factors; traffic accidents; tunnels