Speedometers and odometers, when inspected, shall have legible dials and calibrations and register speed and distance traveled in miles or kilometers, or both, and be connected and operable. When the odometer is calibrated only in kilometers, a written notice shall be posted on the instrument panel in full view of the driver, and the notice shall contain the formula for converting kilometers to miles. Example: "Kilometers" divided by 1.609 equals "miles".
Md. Code Regs. 11.13.06.01