Abstract
Understanding the characteristics of strong crosswinds on bridges is important for taking more effective countermeasures against vehicle running safety. The crosswinds on the bridge have been partly evaluated through wind tunnel test or CFD, while little study has been conducted on along-bridge evaluation by field measurement. Therefore, we investigated the characteristics of the crosswind on the Trans-Tokyo Bay Highway Bridge which has variable-depth box girder based on the field measurement by using a vehicle crossing the bridge. On the measurement day, the inflow wind speed was as high as about 13m/s, and the wind direction was perpendicular to the bridge axis. The measurement results on the most windward lane showed that the effects of the larger bridge girder height were significant in decreasing the wind speed. Still, some intermittent high wind speed was observed, too. The cause was the difference in the height of shear flow separated from the leading edge of the bridge girder. In the measurement result on the most leeward lane, the effects of girder height were less observed due to entrainment．
