The commission shall prescribe the forms of applications for certificates and permits, and promulgate rules regarding the contents and filing of applicants, and is empowered to administer and enforce this act, and to establish and enforce rules affecting the operations of all motor carriers subject to this act affecting their use of the highways, and affecting the conduct of investigations and hearings authorized in this act, and also with respect to all matters pertaining to the proper enforcement of this act. The rules shall be promulgated under the administrative procedures act of 1969, 1969 PA 306, MCL 24.201 to 24.328. The rules may be rescinded, suspended, modified, and amended at any time in the discretion of the commission and as provided in the administrative procedures act of 1969, 1969 PA 306, MCL 24.201 to 24.328, to effectuate the purposes of this act. All rules promulgated by the commission shall have the force and effect of law.