Abstract | A methodology is introduced for the optimal multi-criteria performance-based design of highway bridges under seismic loading based on the concept of Incremental Dynamic Analysis (IDA). IDA is a novel analysis method that can thoroughly estimate the seismic demands and limit-state capacities of a structure under seismic loads by subjecting it to a suite of ground motion records that are suitably scaled to several levels of intensity. The mean annual frequencies (MAFs) of exceeding each limit-state become readily available when combining the results with probabilistic seismic hazard analysis. By thus analyzing each alternate design we are able to directly apply the desirable constraints on the acceptable performance of the bridge and employ evolutionary strategies to perform Pareto optimization and minimize the bridge cost and the MAF of collapse. As an example, the Pareto set is generated for a typical two-span bridge with a single-column pier and a prestressed concrete deck supported on elastomeric bearings. It is shown that improving the bearings provides an inexpensive increase in collapse performance, but further gains necessitate costly strengthening of the pier column. The procedure presented is resource-intensive but highly accurate. It provides important information on the influence of design parameters on the bridge performance and allows their optimal selection.