A steering system (10) for a vehicle, such as a gantry crane (12). The gantry crane (12) generally includes a support structure (14) having a first front wheel (32) and a second opposing front wheel (36) connected proximate a front portion of the crane (12), and a first rear wheel (30) and a second opposing rear wheel (34) connected proximate a rear portion of the crane (12). A control system connected to the crane includes a user interface (111) electronically coupled to a command potentiometer (114) and a programmable controller responsive to the command potentiometer for controlling the angular position of each of the first front wheel (32), the second front wheel (36), the first rear wheel (30) and the second rear wheel (34) to effect a steering mode selected through the user interface (111).