Rule 113
You MUST ensure all sidelights and rear registration plate lights are lit between sunset and sunrise use headlights at night, except on a road which has lit street lighting. These roads are generally restricted to a speed limit of 30 mph (48 km/h), or 20mph (32km/h) in Wales, unless otherwise specified use headlights when visibility is seriously reduced (see Rule 226 ). Night (the hours of darkness) is defined as the period between half an hour after sunset and half an hour before sunrise. Laws RVLR regs 3 , 24 & 25 (In Scotland - RTRA sect 82 (as amended by NRSWA , para 59 of sched 8) ), RR(20)O