• 林 治平

Student thesis: Doctoral Thesis


In Taiwan over one-third of the crashes occurring at highway-rail grade crossings (HRGXs) are fatal and result in serious train delays In addition more than 3 000 auto-barrier gates were broken by highway vehicles every year before 2006 It is therefore a critical issue for the Taiwan Railways Administration (TRA) to eliminate traffic collisions at HRGXs This research develops several integrated models to explore the causal relationships between crash frequency/ gate-breaking frequency and specific risk factors as well as to investigate the effects of respective countermeasures on preventing HRGX incidents Especially sight distance of locomotive engineer (train driver) is the first time to be converted into time factor (TTA) for the HRGX crash analysis A classification regression model was employed to investigate the causal relationship between time to train arrival (TTA) and crash frequency Also HRGX with a shorter TTA is validated having significantly associated with higher crash rate The CCY-TTA regression equations are successfully functional to explore collision trend in the conjunction table which is paired by HRGX attributes and crash characteristics Meanwhile HRGX with a higher gate breaking frequency is likely to have higher traffic collision frequency The logistic regression models were developed for the analysis of gate-breaking frequencies in which three highway vehicle modes were analyzed under three gate breaking types Every mode shows various consequences of gate-breaking frequency by different HRGX attributes Especially heavy vehicles conducting half of gate-breaking incidents are easier to break the gates at the HRGX near intersection than that near station In addition a three-layer hierarchical model toward incidents related to heavy vehicles was developed to identify the key factors and combination of the factors that best explain crash and gate-breaking frequency Further the before-and-after effects of three control and warning devices including law-enforcement camera and video LED train approaching indicator and obstacle detector on the reduction of crash/gate-breaking rates were evaluated The pure and interaction effects of these three advanced devices on improving the safety levels of HRGXs were analyzed As a result the small marginal effectiveness of combined two and three advanced devices means that an over-investment was at some HRGXs in Taiwan Finally a risk assessment conducted by assigning the methodology of the risk evaluation process is carried out in order to analyze the total risk and average risk levels for an HRGX By comparing before and after existing countermeasures in different periods the results in terms of risk evaluation of an HRGX would therefore be beneficial to the TRA to reduce HRGX crashes and gate-breaking incidents
Date of Award2015 Feb 12
Original languageEnglish
SupervisorShou-Ren Hu (Supervisor)

Cite this