It shall be the duty of the State Highway Commission to have the State Highway Department maintain all highways which have been or which may be hereafter taken over by the State Highway Department for maintenance in such a way as to afford convenient, comfortable, and economic use thereof by the public at all times. To this end it shall be the duty of the director, subject to the rules, regulations and orders of the commission as spread on its minutes, to organize an adequate and continuous patrol for the maintenance, repair, and inspection of all of the state-maintained state highway system, so that said highways may be kept under proper maintenance and repair at all times.