GOALS
considerations:
• viewing angle must be no less than 30 degrees
• is guarded from sunlight
• how many years does it last?
heat concern:
• shortens lifespan
• can dim light
• affects color
our light should be:
• Energy-efficient
• Rugged and durable
• Provide sufficient quantity and quality of light for pedestrians to walk safely
• Do not produce light pollution or light trespass
Light pollution/focus
• aim
• lower
• shade
On partial right of way:
Flashing yellow lights mean proceed with care. They require cars to treat them like stop signs. Since drivers already know this signal/rule, it would be easier to implement than a totally new symbol/rule for pedestrians. This source is a wealth of information about turning laws in different countries in regards to red light cameras (will we be using that technology with the sensors?).
Buy a traffic light from China.
Key Specifications/Special Features:
* Materials: PC or aluminum
* Rated power: 8W/unit
* Power consumption: > 8W
* Working voltage: 220V AC±20%
* Frequency: 50 to 60Hz
* Lifespan: up to 50,000 hours
* Can save up to 80 to 90% energy
* Wavelength:
o Red: 620nm
o Yellow: 590nm
o Green: 505nm
* Temperature: -40 to 75°C
* Humidity: > 90%
This graph is part of research done by RPI which has many more graphs for us to utilize for comparison of lumens. Sam, you asked for lumens for LED traffic lights and this is the most legit source I could find. Unfortunately, we're gonna have to interpret a little bit. We should compare this information with the afformentioned traffic light from China. We should also read the .pdf together that is located here.
Two positives about LED traffic lights include gradual burnout (vs. immediate burnout by incandescents) and lifespan of up to ten years (as of 2002). Is there more specific, up to date info? Here are some more stats, but I think we should have more specific stats to a specific size/brand of light...but I can't find any!!!
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