Md. TRANSPORTATION Code Ann. § 21-312

§ 21-312. Entering or leaving controlled access highways

(a)  Driving vehicle onto controlled access highways. —  A person may not drive a vehicle onto any controlled access highway except at the entrances and exits established by public authority.

(b)  Driving from controlled access highways. —  A person may not drive a vehicle from any controlled access highway except at the entrances and exits established by public authority.