Street lighting provides a number of important benefits. It can be used to promote security in urban areas and to increase the quality of life by artificially extending the hours in which it is light so that activity can take place. Street lighting also improves safety for drivers, riders, and pedestrians.
The principal purpose of street lighting is to produce quick, accurate and comfortable visibility at night. These qualities of visibility may safeguard, facilitate and encourage vehicular and pedestrian traffic. When good visibility is provided through lighting, efficient night use can be made of the large investments in roadways and motor vehicles. Thus, the proper use of street lighting as an operative tool provides economic and social benefits to the public such as:
1.reduction in night accidents, attendant human misery and economic loss
2.aid to police protection and enhanced sense of personal security
3.facilitation of traffic flow
4.promotion of business and the use of public facilities during the night hours
The purpose of street lighting is to assist drivers, pedestrians, and cyclists in finding their way in the dark. Many neighborhood groups believe that extra illumination helps prevent crime, and business district lighting also may help create a pleasant environment. If your community group is thinking of adding or replacing some lamps (as the sales and technical people call them), this page will give you an overview of the considerations.
Photocells now turn most of them off and on according to the actual amount of available light, so we’ve come a long way since lamplighter days. Now we rely on high intensity discharge lamps. LED lighting is coming on strong for focused lighting situations, due to its energy efficiency.
However, you’ll still find many various types of fixtures in use now including the older mercury vapor, sodium vapor or high pressure sodium, and metal halide.
Street lighting is not actually aimed at showing the way directly ahead of the automobile; the car lights do that. But it does illuminate adjoining areas to alert drivers to the emergence of possible hazards from the side.
Pole height is extremely important in the way that light is distributed, so transportation engineers typically want to mount the lights higher on higher-speed roads.
To be safe for drivers, light needs to be relatively constant. We know our eyes adjust faster to going out into the sun than to walking into darkness. For awhile when we enter a dark room, our vision is impaired.
Driving from a well-lit area to a dark one produces a similar effect. So ideally if an area must be illuminated, the globes are mounted on high poles fairly close together so that the light stays constant, and the eyes are not continuously readjusting for different levels of brightness.
For pedestrians, the goal often is illuminating the walkway itself. Extra dark spots along sidewalks can be created by a variety of conditions, including trees, rows of large shrubbery, odd angles of the streets, parking patterns, a tall church steeple or other building permitted in a residential neighborhood, or a host of other potential influences.
Keep in mind too that as the popularity of bicycling swings upward, you’ll need to monitor the impact of the presence or absence of lighting on those new bike lanes.