Singapore legislation
Regulation 68
of Road Traffic (Motor Vehicles, Construction and Use) Rules
Regulation 68
Taxi to have illuminated signs
Every vehicle which is a taxi shall be fitted on its roof with a sign of a size, colour and design approved by the Registrar, which shall —
(a)
at all times during the hours of darkness be illuminated when the taxi is available for hire; and (b)be clearly visible from a distance of not less than 20 metres from the front and rear of the taxi.