Modular bridge structures are commonly used in areas where space and weight are major limitations. In this study, a modular bridge structure made of extruded aluminum alloy AA7005 was analyzed using numerical simulations. Parametric model of the bridge structure was produced and optimized for required loading conditions. The aim of the research work was to minimize the weight of the bridge structure without compromising its strength. Sensitivity analysis was performed by taking thickness of the structure member as optimization variable. Optimum thickness of the bridge member obtained from simulations was assigned for the analysis of the entire structure. Results obtained from Finite Element (FE) simulations predicted maximum stress at the center of the structure. Parametric modeling of the structure allowed to asses failure against different loading conditions.