This　paper　presents　a　simplified　method　for　determining　the　dynamic　loading　of　curved　steel　box　girder　bridges　due　to　vehicles　moving　across　rough　bridge　decks.　The　curved　single　box　girder　bridges　are　divided　into　a　number　of　thin-walled　beam　elements.　The　curved　multi-box　girder　bridges　are　modeled　as　a　curved　grillage　system.　The　analytical　vehicle,　simulated　as　a　non-linear　vehicle　model　with　11　degrees　of　freedom,　is　the　HL-93　truck　as　described　in　the　American　Association　of　State　Highway　and　Transportation　Officials　(AASHTO)　specifications.　Truck　parameters　include　the　body,　suspensions,　and　tires.　The　bridge　deck　surface　is　simulated　using　a　stochastic　process　(power　spectral　density　function).　The　dynamic　loading　of　28　three-span　continuous　single　box　girder　bridges　and　216　three-span　continuous　multi-box　girder　bridges,　with　span　lengths　ranging　from　22,83-30,48-22,86　m　to　64,01-85,34-60,01　m　is　analyzed.　The　analytical　results　show　that　the　torsion　impact　factors　for　curved　box　girder　bridges　can　be　relatively　high,　while　moment,　shear,　and　deflection　impact　factors　are　normally　less　than　those　of　corresponding　straight　box　girder　bridges　due　to　restricted　vehicle　speed　on　curved　bridges.　The　proposed　simplified　impact　equations　are　appropriate　for　the　design　of　both　curved　single　box　and　multi-box　girder　bridges.