Md. Code, Business Regulation § 17–909

(a) A peddler license authorizes the holder to act as a peddler only in the county where the peddler license is issued.

(b) In Harford County, a peddler may not sell goods on:

(1) a county right-of-way; or

(2) a State right-of-way, unless the peddler gets a lease agreement from the appropriate State unit.