The effects of rail joints on the dynamic response of bridges have not been quantified. This study measured the displacement of steel railway bridges for more than 1000 cases of train passage. Time-frequency analysis of the response revealed that high-frequency components between 40Hz to 200Hz when wheels pass through rail joints and frequency components of 42Hz and 125Hz immediately after the passage were observed. The presence of rail joints increases the girder dynamic displacement response amplification by a maximum of about 0.02 and 0.08 for a girder with a span of 22.3m and 6.7m, respectively. The amplification tends to increase as the rail joint became larger and the position of the rail joint closer to the span center.
