(a) The speed of a motor vehicle may be proved by evidence obtained by use of any device designed to measure and indicate or record the speed of a moving object by means of microwaves, when such evidence is obtained by members of the Police Department. The evidence so obtained shall be accepted as prima facie evidence of the speed of such vehicle.
(b) In order to inform and educate the public generally that speed of motor vehicles operating within the City is being tested by radar mechanisms, there shall be located and placed suitable and informative stationary and movable signs at strategic points on and along the streets giving notice to the public that such radar mechanisms are in use.
(1970 Code Sec. 19-57)