Hazard Warning Light Diagram
This Can easily be built and added to existing indicator circuit on your trike. The Flasher relay must be a 4x21 watt relay. Using  an electronic relay gives a constant flash rate. The Diodes are a 3 amp device, and are there to allow normal operation of the indicators when the hazards are switched off. Its important to note the polarity when fitting ( make sure white line is as diagram)
If you cant see your front indicators from the riding position, you will also need a light on your instrument cluster to show the hazards are switched on
Now a MOT requirement for trikes
Disclaimer   Use of this information is entirely at your own risk
Tribes Trike Site