Rule 212 - The Highway Code

Give motorcyclists, cyclists, horse riders, horse drawn vehicles and pedestrians walking in the road (for example, where there is no pavement), at least as much room as you would when overtaking a car (see Rules 162 to 167). Drivers should take extra care and give more space when overtaking motorcyclists, cyclists, horse riders, horse drawn vehicles and pedestrians in bad weather (including high winds) and at night. If the rider looks over their shoulder it could mean that they intend to pull out, turn right or change direction. Give them time and space to do so.