Md. Code, Transportation § 24-207

(a) Unless the person has a written permit from the State Highway Administration, a person, whether the owner of the vehicle, the person having charge and control over the vehicle, or an employee or agent of either, may not use any State highway to test any truck, whether for durability, speed, fuel consumption, or otherwise.

(b) The State Highway Administration may issue a permit if, in its judgment:

(1) The highway over which the test will be conducted will not be unduly damaged; and

(2) The safety of the traveling public will not be materially adversely affected by the test.

(c) The State Highway Administration:

(1) Shall designate in the permit the route on which and the day and hour during which the tests may be conducted; and

(2) May impose additional regulations and limitations to promote the safety of the traveling public and prevent undue damage to the highway under its jurisdiction.

(d) For each vehicle to be tested, the permit fee is $25.

(e) A permit is not required for the testing of trucks serviced or repaired by a garage licensed under Title 17, Subtitle 8 of the Business Regulation Article if:

(1) All laws of this article are observed by a garage owner in regard to size, weight, and speed restrictions of the particular type of truck tested; and

(2) All local motor vehicle traffic, speed, and safety ordinances are complied with.