(a) Any rural letter carrier’s motor vehicle may be equipped with a warning device for the purpose of warning the drivers of other vehicles of the presence of a vehicular traffic hazard requiring the exercise of unusual care in approaching, overtaking, and passing, and, when so equipped, may display the device in addition to any other warning signal required or permitted by law.
(b) The warning device shall include two bi-directional lights mounted at each side of the vehicle on the roof, with two amber lenses facing the rear and two amber lenses facing the front.
(c) Each light shall be at least 4 inches in diameter and shall be powered by a bulb of at least 21 candlepower, with reflectorization sufficient to assure visibility for at least 500 feet in front of and to the rear of the vehicle.
(d) The lights shall be wired with one “on-off” switch and one “flashing” switch, which shall activate both lights simultaneously, and which may be wired to operate from the vehicle’s stoplight switch.
(e) Between each light on the assembly of the device a sign shall be mounted with the words “U.S. Mail” in black letters on a white background, facing both to the front and the rear.
(f) The lettering on the sign shall be at least 4 inches in height, and the width of each stroke shall be at least 3/4 of an inch.
(g) The sign shall be constructed to permit it to be folded down out of vision when not in use.
(h) The warning device may be used only during the discharge of a rural letter carrier’s official duties.
(i) Before the first stop on the route and following the last one the lights shall be darkened and the sign folded down out of vision.
(j) The warning device may not be installed or operated until an application has been submitted to and approved by the Administration.
(k) The application shall be made by the individual rural letter carrier on forms furnished by the Administration.
Structure Maryland Statutes
Title 22 - Vehicle Laws -- Equipment of Vehicles
Subtitle 2 - Lamps and Other Lighting Equipment
Section 22-201 - "Service Vehicles" Defined
Section 22-201.1 - When Lighted Lamps Are Required
Section 22-201.2 - Use of Headlights When Windshield Wipers Are Operated
Section 22-202 - Visibility Distance; Measuring Mounted Height of Lamps
Section 22-203 - Headlamps on Motor Vehicles and Motorcycles
Section 22-204 - Tail Lamps; Illumination of Rear Registration Plate
Section 22-206 - Stop Lamps and Turn Signals
Section 22-208 - Clearance, Identification, and Marker Lamps and Reflectors Required
Section 22-210 - Mounting of Reflectors, Clearance Lamps, and Side Marker Lamps
Section 22-212 - Obstructed Lamps Not Required to Be Lighted
Section 22-213 - Lamps, Reflectors, and Flags on Projecting or Extended Loads
Section 22-214 - Lamps on Parked Vehicles
Section 22-215 - Lamps on Farm Tractors and Farm Equipment
Section 22-215.1 - Rollback Vehicle Operated in Combination With Vehicle Being Towed
Section 22-216 - Lamps on Other Vehicles and Equipment
Section 22-217 - Spot Lamps, Fog Lamps, and Auxiliary Driving Lamps
Section 22-218 - Audible and Visual Signals on Vehicles
Section 22-218.1 - Rural Letter Carrier's Warning Device
Section 22-218.2 - Amber Lights on Tow Trucks, Escort, and Maintenance Vehicles
Section 22-219 - Signal Lamps and Signal Devices
Section 22-221 - Additional Lighting Equipment
Section 22-222 - Multiple-Beam Road-Lighting Equipment
Section 22-223 - Use of Multiple-Beam Road-Lighting Equipment
Section 22-225 - Alternate Road-Lighting Equipment
Section 22-226 - Number of Driving Lamps Required or Permitted
Section 22-227 - Special Restrictions on Lamps
Section 22-228 - Special Equipment on School Vehicles
Section 22-230 - Selling or Using Lamps or Equipment
Section 22-232 - Revocation of Certificate of Approval on Lighting Devices