Two-Day Radio For London's Motor Cycle Police Under Radio Control from H.Q. when mobile the motor cyclist is warned by the orange lamp (on left of handlebar). When stationary the buzzer is switched into operation. London Is always up-to date in its fight against crime. Latest innovation by Scotland Yard is the fitting of two-way radio to police motor cycles. This enables the mobile police to be in constant communication with headquarters. Scotland Yard's information room can call .them individually or in a group and a motor cyclist can himself report any incident immediately." February 05, 1951. (Photo by Paul Popper Ltd.).