When trains run on a curved track, wheel and rail vibrations sometimes cause squeal noise (below 10 kHz) and high-frequency noise (above 10 kHz), contributing greatly to overall wayside noise and often causing complaints from residents. The measurements of noise and vibrations were conducted in commercial lines to understand the mechanisms underlying the generation of these noises and develop methods to reduce them. It is found that the occurrence of these noises varied from train to train, and the magnitude and dominant frequency at which they occurred varied greatly from wheel to wheel. Furthermore, the analysis of the results showed that these noises become prominent both inside and outside when outer wheel flanges contact outer rail.