Strong crosswinds sometimes cause vehicle accidents on a bridge. Traffic regulations such as speed restriction and bridge closure are enforced to prevent these accidents. Wind fields on a bridge deck are complex and key parameters to affect crosswind-induced vehicle accidents. In addition, not only bridge structures but also vehicle itself cause complex wind fields on a bridge deck. This study investigates vehicle interaction effects of aerodynamic forces on a vehicle running on a bridge by using a specially developed model vehicle driving and its aerodynamic force measurement devise in a wind tunnel. It was found that a windward vehicle largely changes aerodynamic forces on a leeward vehicle by aerodynamic interaction. In particular, an overshoot phenomenon in the side force and yawning moment was observed just after vehicle passing.
