It's actually 200 yards; and there has to be a system of "carriageway" lights not "footway" lights. This all depends on the height of the light. If the lights are less than 13ft high, they are automatically "footway" lights. Between 13 and 20 ft they are "footway" lights if over 50yds apart and "carriageway" lights if less than 50 yds apart. Lights over 20 ft high are "carriageway" lights, but also have to be no more than 200yds apart.
Anyone measured the height and spacing of the lights when they got done?