The UK road marking made from short white lines across a lane that warns of a hazard ahead is called a hazard warning line.
Hazard warning lines are placed where drivers need to pay particular attention, such as before a junction, bend, hump bridge, pedestrian crossing, or other obstruction. They are normally longer and closer together than ordinary lane-divider markings, helping drivers recognize that the road layout requires extra care.
This marking is not the same as a stop line. A stop line is a solid transverse line that marks where a vehicle must stop at signals, a stop sign, or another mandatory control. It is also different from a give-way line, which uses short double-dashed markings and supports a give-way instruction.
The UK’s road-marking conventions are described in the Highway Code and related regulations. Exact placement depends on the hazard and road design, so the marking works as a visual warning rather than as a standalone speed limit.