The (Louisville) Courier-Journal included an interesting story on technology that is improving traffic signals.
The new lights not only are a lot more energy efficient but they are easier to see. They also last longer than the old lights, so maintenance crews will spend less time (theoretically) tying up traffic to replace them.
The City of Denver started the change back in 1996 by switching out the red lights. The city says it has saved a bundle. HowStuffWorks.com explains the technology.
The C-J story said:
Traffic signals that use incandescent bulbs are becoming extinct, as cities and states, including Louisville, Kentucky, and Indiana, swap them for a new type of light that saves energy and money -- and possibly lives.
The regional switch to signals that use light-emitting diodes, or LEDs, lags behind many cities and states, including Denver, Minneapolis, and California.
Waiting for technology to improve and the cost of the new lights to drop was a good strategy, said Pat Johnson, a senior traffic engineer for Louisville metro government.
"Now, the cost has come down to where it's a no-brainer," Johnson said. "If you didn't use LEDs ... you'd be stupid."
The LED traffic signals are about 85 percent more energy efficient.
I really did not think traffic signals used much electricity, but when you consider how darn many of them there are, a little saving on each light adds up. The story said Kentucky transportation officials could see a $1.6 million a year savings. HowStuffWorks.com explains the savings kick in.
The energy savings of LED lights can be huge. Assume that a traffic light uses 100-watt bulbs today. The light is on 24 hours a day, so it uses 2.4 kilowatt-hours per day. If you assume power costs 8 cents per kilowatt-hour, it means that one traffic signal costs about 20 cents a day to operate, or about $73 per year. There are perhaps eight signals per intersection, so that's almost $600 per year in power per intersection. A big city has thousands of intersections, so it can cost millions of dollars just to power all the traffic lights. LED bulbs might consume 15 or 20 watts instead of 100, so the power consumption drops by a factor of five or six. A city can easily save a million dollars a year by replacing all of the bulbs with LED units. These low-energy bulbs also open the possibility of using solar panels instead of running an electrical line, which saves money in remote areas.
On top of that, the people in Kentucky expect to save on maintenance. The Courier-Journal said:
Officials anticipate an additional $1.5 million savings in reduced maintenance costs annually, because LED lights are expected to last more than 10 years, compared with incandescent bulbs that burn out and need to be replaced every eight to 10 months.
The amount of energy saved would be equivalent to the power needed for 3,000 homes while reducing carbon-dioxide emissions, which many scientists blame for global warming.
Similar conversions are taking place from California to Massachusetts, as the cost of the new lights keeps dropping and agencies recognize how much money and energy they can save, said Howard Newman, spokesman for the Consortium for Energy Efficiency Inc. in Boston.
Indiana began installing energy-efficient traffic lights on state-maintained roads about four years ago, and some cities are also putting them in, said Susan Dillman, spokeswoman for Indiana Department of Transportation.
"We're retrofitting our incandescent light intersections at a rate of about 16 percent a year," she said.
Unlike an incandescent bulb, an LED light has no filament that can burn out. LED light is the result of electrons moving on a semiconductor material.
In addition to longer life and less maintenance, the LEDs provide a brighter signal, which makes them more visible to motorists.
With incandescent bulbs, drivers see a single bright spot from a glowing bulb behind red, yellow, or green lenses.
The LEDs, however, are arrayed in a honeycomb pattern made up of more than 100 tiny lights for each signal color.
The story says LED lights cost $225-$250 for a three-light traffic signal, compared with about $150 for the older incandescent signals.
The Bully ProjectLast summer, I
told Al's Morning Meeting readers about a project that WITI (in Milwaukee) did that really caught my attention.
The Bully Project involved surveying 13,000 students and teachers from area schools about the problem of bullying. WITI learned the problem was far more widespread than teachers and parents thought.
Now, WCPO-TV in Cincinnati has taken on the project. The station surveyed 13,000 students and 600 teachers in 41 schools.
Just as WITI had found, WCPO watched school playgrounds and witnessed clear acts of aggression and violence. The station's website includes video, the raw results of the survey, and -- interestingly -- also includes message boards for students, as well as for educators and parents.
The WCPO survey found:
- 40 percent or 4 of 10 students say they've been bullied
- 30 percent or one of three students say they've bullied others
- 59 percent say they've been bullied verbally, 42 percent physically and 42 percent ignored/excluded
- Most students, 28 percent say bullying happens in classroom followed closely by 27 percent lunchroom, and 22 percent playground
Serious School Violence Goes Unreported
In Seattle, KIRO-TV took the idea further. Reporter Chris Halsne found that in Tacoma, sexual assaults and fistfights between students are "vastly underreported" and are kept secret from police and parents.
The station provided some pretty startling statistics:
In the past two years alone, at least 873 Tacoma high school students were disciplined for assaulting, raping, beating, stabbing, or robbing each other on classroom property.
We open your eyes to what districts have long kept hidden from public scrutiny.
Stadium High in Tacoma is a school made for movies -- gorgeous on the outside, a diverse student body, a solid football team.
Inside the halls and bathrooms and classrooms, however, it's been a bloody violent two years: Four sexual assaults, 68 additional unprovoked, aggravated assaults, plus at least 78 separate fights.
In all, 225 Stadium High students have been expelled or suspended for acts of violence. The statistics are not shared with anyone, not parents, not school board members, not the state superintendent.
Gold Hits 16-year HighFutures topped $450 an ounce yesterday.
You could try contacting gold jewelry and coin buyers to see if people are selling stuff to cash in on the high prices.
It will be interesting to see if the high price of gold affects jewelry sales. In other parts of the world, it already has.
Boy Scouts and Military Bases
Al's Morning Meeting reader Scott Burgess, at
Stars and Stripes sent me a note about my Monday column, which mentions a new Pentagon order forbidding military installations from sponsoring Boy Scout troops.
Stars and Stripes points out that individuals may still participate in sponsoring and leading Boy Scouts. And, Boy Scouts are still allowed to meet on federal property despite the ruling.
Spirits for the Christmas Tree
Al's Morning Meeting reader Ellie Estrada at KMTR in Eugene, Oregon, tells me that she found a man who claims to have kept a tree green until Valentine's Day. The secret, he says, is to add some vodka to the water.
We are always looking for your great ideas. Send Al a few sentences and hot links.
Editor's Note: Al's Morning Meeting is a compendium of ideas, edited story excerpts, and other materials from a variety of websites, as well as original concepts and analysis. When the information comes directly from another source, it will be attributed, and a link will be provided, whenever possible.
LED lights may have a major public safety flaw that...
