StreetLightNews

In order to increase the safety of night-time driving on UK motorways, and additionally lower CO2 emissions, the Lancashire County Council decided to equip a stretch of motorway M65 with a dimmable lighting system controlled by traffic flow. The system can be dimmed with up to 30%, and is equipped with an intelligent controller and a two-way remote communication facility. Additionally, it offers individual control of luminaires, event reports and constant monitoring functions of the installation.
The project came about when lighting fixtures at a specific stretch of the motorway had to be renewed. The previous installation was controlled by photocells mounted at each feeder pillar, switching the lights on and off through a contactor. The lighting levels were constant throughout the night. The luminaires in the old installation were also emitting excess light beyond the boundaries of the highway, contributing to light pollution in the surrounding area.A replacement plan was implemented in order to link the lighting level to the traffic flow, reduce the power consumption and to monitor possible lamp defects.
Through already existing traffic counters which continuously monitor the amount of cars on the motorway, the lighting levels are adjusted to preset levels depending on the traffic flow.With more than 3,000 cars per hour, the lighting level was kept full on. With 1,500 to 3,000 cars per hour, the lights were dimmed to 75, and with less than 1,500 cars, lights were dimmed to 50%.
The new luminaires allow for ‘soft’ switching when shifting from one level to another, avoiding sudden changes in the lighting levels. Additionally, traffic safety is judged to be increased because dimming, opposed to e.g. turning off every other light as a savings measure, provides protection from a flickering or strobing effect.The completed pilot has shown that not only has the stretch of motorway gained better lighting quality and improved control, CO2 emissions are lowered 274 tons to 129 tons through a combination of the dimming, traffic flow control and the new luminaires. Read more here…

This entry was posted on Wednesday, August 1st, 2007 at 12:41 pm and is filed under improved lighting, environmental benefits, dimming, energy savings. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.