The　impact　of　seven　three-span　continuous　single　box　girder　bridges,　with　overall　span　lengths　ranging　from　76.2　to　213.36　m　(250-700　ft),　due　to　vehicles　moving　across　rough　bridge　decks　is　analyzed.　The　box　girder　is　divided　into　a　number　of　thin-walled　beam　elements.　Both　warping　torsion　and　distortion　are　considered　in　the　study.　The　analytical　vehicle　is　the　HS20-44　track　included　in　the　American　Association　of　State　Highway　and　Transportation　Officials　specifications　and　simulated　as　a　nonlinear　vehicle　model　with　11　degrees　of　freedom.　Truck　parameters　include　the　body,　suspensions,　and　tires.　The　bridge　deck　surface　is　assumed　to　be　good　and　was　simulated　using　a　stochastic　process　(power　spectral　density　function).　The　analytical　results　show　that　the　impact　factors　of　torque　and　distortional　torque　for　the　curved　single　box　girder　bridges　could　be　very　high,　while　those　of　the　other　responses　are　generally　less　than　that　of　corresponding　straight　box　girder　bridges.　The　proposed　impact　equations　can　be　used　in　the　design　of　continuous　curved　single　box　girder　bridges.