Rule 115

You should also

  • use dipped headlights, or dim-dip if fitted, at night in built-up areas and in dull daytime weather, to ensure that you can be seen
  • keep your headlights dipped when overtaking until you are level with the other vehicle and then change to main beam if necessary, unless this would dazzle oncoming road users
  • slow down, and if necessary stop, if you are dazzled by oncoming headlights.