CA mortar	Cement-emulsified asphalt mortar	CBM	Condition-based maintenance
CIT	Comprehensive inspection train	CRTS	China Railway Track System
DIC	Digital image correlation	DWT	Discrete wavelet transform
EMU	Electric multiple unit	GIA	Grey incidence analysis
GPR	Ground-penetrating radar	GRA	Grey relational analysis
HSR	High-speed rail	HSTGC	High-speed track geometry car
NDT	Non-destructive test	PDF	Probability density function
PSD	Power spectrum density	RMS	Root mean square
SWD	Slab-warping deformation	SWI	Slab-warping index
TGC	Track geometry car	TGC	Track geometry index
TQI	Track quality index	TRI	Track roughness index