A higher order finite strip formulation based on the auxiliary nodal line (A.N.L.) technique for a dynamic analysis of curved box-girder bridges is presented. Newmark's equations of numerical integration have been applied depending on the values of the coefficients (  ,), and adopted in the current study with a value equal to (0.5, 0.25) of a curved box girder bridge with simple support and exposed to the traffic of the moving vehicles represented by the system of the moving force. Where the dynamic interaction between the vehicle and the bridge is neglected. The study has also required the application of Newmark's method to find out the dynamic response values represented by (deflections, dynamic amplification factor, Impact factor) to solve the issues related to the bridge loaded by moving vehicles model. Each system is composed of a suspended mass joined with a damper and a spring of stiffness in addition to the unsuspended mass.