A broken white line. This marks the centre of the road. When this line lengthens and the gaps shorten, it means that there is a hazard ahead. Do not cross it unless you can see the road is clear and wish to overtake or turn off.
Section: General rules, techniques and advice for all drivers and riders (rules 103 to 158) Subsection: Lines and lane markings on the road (rules 127 to 132)All Highway Code Rules | My Saved Highway Code Rules