In order to realize safer railway transportation, a new type monitoring bogie which can measure continuous value of derailment coefficients in service operation has been developed. Using the monitoring bogie, running safety is quantitatively evaluated and is potentially effective for protective maintenance of track. There are numerous factors affecting the value of derailment coefficient, alignment irregularity is one of them. In this research, an effect of alignment irregularity which affects the fluctuation of derailment coefficient along curved section is studied based on multi-body dynamics simulation in terms of lateral creepage of the leading wheelset along alignment irregularity.
