Campus Lights

Photos and Text by Gary Cziko
University of Illinois
g-cziko@uiuc.edu

Green Street West of Wright Street

Green Street of UIUC's Campustown west of Wright St. Notice how both the high and low tear-drop shaped street lamps produce as much glare as the headlights of the approaching car. These lights send most of their light sideways and upward and are therefore very inefficient in putting light on the sidewalks and street. They also are a source of light pollution, helping to destroy dark skies.

Tear-Drop Shaped Lamps of Campustown

Some might consider this a pretty light. The trouble is, it sends most of its light sideways and upwards, making it very inefficient in getting light on the ground. It also causes glare and is wasteful in producing light pollution and destroying dark skies. Decorative, yes. Functional, no. Street lights are not like Christmas lights on a tree. The latter should be seen. The former should be "hidden" as much as possible so that light is directed to and reflected off the surfaces to be illuminated, not sent directly into a person's eyes.

Sixth Street North of John Street

Looking down on Sixth Street north of John Street from the top level of the parking deck. . The glare of every street lamp is apparent with lots of light being sent sideways and skyward. The sidewalk and street qre well lit only because there are so many lights burning lots of watts with most of the electricity consumed creating light which is wasted.

Sixth Street South of John Street

This is Sixth Street south of John Street. Notice how much more efficient these "old style" street lamps are in directing their light downward rather than sideways and upwards. It is hard to even know where the lamps are without first finding the poles they are mounted on. When bicycling at night, I find this section of Sixth Street much easier on my eyes without the glare of the lights north of John Street.

This document can be accessed at http://uiuclights.notlong.com

For more information about light pollution, its advserse effects, and the technical and legislative means to reduce it, see
http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightpollution/abstract.asp As of January 2003, 17 U.S. states had adopted or pending legislation governing light pollution.

For information on cities using LEDs for street lights, see http://ledcity.org
Advantages of LED lights: use less energy (save 40 to 70%), longer service life, more directional, can control color to enhance mesotropic vision providing better visibility with less light power. UIUC professor Nick Holonyak, Jr., is considered the "father of the LED."