A neural stimulation system delivers neural stimulation to a target nerve with control of direction of propagation of evoked neural signals in one or more fiber types of the target nerve using electrode configuration, thereby providing effective therapy while minimizing unintended effects. In various embodiments, mechanical parameters of a multi-polar electrode are determined to provide directed propagation of the neural stimulation by effecting neural conduction block in or near the stimulation site. In various embodiments, the electrode includes a cathode for evoking action potentials and a plurality of anodes for blocking the propagation of the evoked action potentials in specified direction(s) and fiber type(s) while minimizing the formation of virtual cathodes.