The primary function of highway bridges is to ensure the safe passage of truck and traffic loads between different origin and destinations across a nation.However,a negligible amount of research exists on the influence of live loads on the seismic reliability of highway bridges which typically consists of multiple vulnerable structural components.This study investigates the influence of the standard HS-20 truck load,widely adopted in live load reliability studies,on the seismic response of bridge components and system depending on the location of the truck atop the bridge deck.