1. A computer-implemented method for determining a steering rate for operating an autonomous vehicle, the method comprising: determining a plurality of steering rate candidates for a steering control command of operating an autonomous vehicle; for each of the steering rate candidates, calculating a plurality of individual costs for the steering rate candidate by applying a plurality of cost functions, each cost function corresponding to one of a plurality of cost categories, and calculating a total cost for the steering rate candidate based on the individual costs produced by the cost functions; selecting one of the steering rate candidates having a lowest total cost as a target steering rate; and generating a steering control command based on the selected steering rate candidate to control a steering wheel of the autonomous vehicle.