Maryland Code, Transportation § 21-704

(1) A normal operating speed of 10 miles per hour or less; or

(2) A vertical body or load clearance, measured above the level surface of a roadway, of less than:

(1) Notify an agent of the railroad of his intention; and

(2) Afford the railroad reasonable time to provide proper protection at the crossing.

(1) Shall stop within 50 feet but not less than 15 feet from the nearest rail in the crossing;

(2) While stopped, shall listen and look in both directions along the track for any approaching or passing railroad train and for any signals indicating the approach or passage of a railroad train; and

(3) May not proceed until he can do so safely.

(d)(1) The person may not proceed if a warning is given by an automatic signal, crossing gate, flagman, or otherwise of the immediate approach or passage of a railroad train.

(2) If the railroad provides a flagman, the person may proceed over the crossing only at the direction of the flagman.