Once the destination of the first passenger or first group of passengers to enter a taxicab has been determined pursuant to § 808, the driver may display a sign on the windshield which indicates the direction or location to be traveled.
No driver shall display any sign indicating the direction or location to be traveled until such time as a passenger has occupied the taxicab and the passenger's destination has been determined.
Directional signs displayed pursuant to this section shall be displayed at the bottom of the right half of the windshield so as to not obstruct the driver's vision. The signs shall be uniform in size and letters, and the letters shall be a minimum of two inches (2 in.) in height.
D.C. Mun. Regs. tit. 31, r. 31-809