In the exercise of its powers within its geographical boundaries, an authority is exempt from the motor carrier act, Act No. 254 of the Public Acts of 1933, being section 475.1 to 479.20 of the Michigan Compiled Laws; the motor bus transportation act, Act No. 432 of the Public Acts of 1982, being section 474.101 to 474.141 of the Michigan Compiled Laws; and the public service act.