Safety First. The highly accurate Lightsign Doppler Radar display system is a clear speeding deterrent used by local authorities or private management companies. Affordable and highly effective Using Ultrabright LEDs the single colour RED or Bi-Colour Amber/Red or Green/Red speed indicator instantly draws attention to the drivers speed and if excessive allowing them to reduce to the regulated limit when the warning ceases. The system is cost effective, Robust, Vandal proof and can be powered without cost using Solar energy.