4 ms·

Most are turned on locally by a photocell mounted on the street light.

• danbruc 9y ago
  There is then probably considerable variation from place to place, but in Germany they usually follow a schedule turning on and off at specific times. It is also not uncommon that every second or so street light gets turned off late in the night. Sometimes they also turn on outside of the usual hours if it is especially dark due to dense clouds or heavy snowfall but I can not really tell whether this is sensed locally at the street light or centrally controlled. EDIT: Just checked the German Wikipedia article and at least here all kinds of different systems with varying levels of granularity and autonomy are in use. Some cities seemingly even installed systems that allow turning on the street lights in specific streets or areas on demand via call or SMS during the late night.
  • zeeZ 9y ago
    In Germany the most common is centrally controlled. Usually a couple streets are connected to a controller, which is either triggered by a signal modulated over the regular mains from the local power provider or a central sensor, or triggered by a sensor connected to the controller. It's usually not individual lamps, but large streets, blocks, or entire neighborhoods at once.
  • chrido 9y ago
    Some are controlled remote using unidirectional long range radio, called "Funkrundsteuertechnik".