Maryland Transportation Section 8-740
§ 8-740.
  (a)   Except as otherwise provided in this section, this part regulates the erection and maintenance of an outdoor sign along or near an expressway, only if:
    (1)   The sign is 660 feet or less from the nearest edge of the right-of-way of the expressway; or
    (2)   The sign is:
      (i)   More than 660 feet from the nearest edge of the right-of-way of the expressway;
      (ii)   Wholly or partly visible from the main traveled way of the expressway; and
      (iii)   Intended to be read from the main traveled way of the expressway.
  (b)   Except as provided in § 8-743 of this subtitle as to the removal of nonconforming signs, this part does not apply to:
    (1)   An outdoor sign that is 660 feet or less from the nearest edge of the right-of-way of an expressway, if the sign was erected on or before June 1, 1959; or
    (2)   An outdoor sign that is more than 660 feet from the nearest edge of the right-of-way of an expressway, if the sign was erected on or before July 1, 1975.