ts-pa
12-18-2009, 09:56 PM
My firefighter brother told me about this possibility....
http://tech.yahoo.com/blogs/null/158097/when-leds-go-wrong-snow-covered-stop-lights/;_ylc=X3oDMTI1a210M2RpBFJfYWlk AwRSX2RtbgN5YWhvby5jb20EUl9maW QDYzZmMGRmYTY3ZWU3NzE5MjA4M2My ODIzMDViNDRmODIEUl9sdHADMQ--
When LEDs go wrong: Snow-covered stop lights
Fri Dec 18, 2009 11:45AM EST
See Comments (http://tech.yahoo.com/blogs/null/158097/when-leds-go-wrong-snow-covered-stop-lights/;_ylc=X3oDMTI1a210M2RpBFJfYWlk AwRSX2RtbgN5YWhvby5jb20EUl9maW QDYzZmMGRmYTY3ZWU3NzE5MjA4M2My ODIzMDViNDRmODIEUl9sdHADMQ--#see_comments) (13)
Buzz up!15 votes http://a323.yahoofs.com/ymg/null__17/null-302757133-1261154298_thumb.jpg?ym6PUYCDE VwA7l17 (http://us.lrd.yahoo.com/_ylt=AgFFqpVOJV7yQwJgLgBMJg3PM ZA5/SIG=12qsg6o6o/**http%3A//a323.yahoofs.com/ymg/null__17/null-302757133-1261154298.jpg%3Fym6PUYCDEGoh8 5VP)Yay for power savings: Putting LEDs in stop lights means that intersections around the country use less energy to keep those red, green, and yellow lights burning 24 hours a day. By some measures, LCD lighting uses 90 percent less energy than incandescent lighting does, and the bulbs last much, much longer before burning out (thus requiring less manpower to constantly replace them). The bottom line is that it all adds up to significant savings for municipalities when spread out over many years.
It all sounds fine and dandy... but a catch is now becoming evident. Because LEDs don't get hot, they can't melt snow (http://news.yahoo.com/s/ap/20091215/ap_on_re_us/us_snow_covered_stoplights;_yl t=Atf.iYYyjYEEZqAcZSLrmvbPMZA5 ). Why is this important? Because in wintry climates, traffic signal alcoves regularly fill up with the white stuff, obscuring the lights behind them. Result: Drivers don't see red lights, and sometimes they plow through the intersection in their obliviousness. At least one driver has likely died as a result of snow-obscured traffic signals, and probably more.
The fix, for now, is decidedly old-school. After heavy snowfall, crews roll out to each intersection and clean the snow out by hand. It's labor-intensive and expensive... and it probably negates a large portion of the cost savings from using LEDs to begin with.
Now the hunt for a tech fix is underway -- whether that means adding weather shields to lights, coating them with a water/snow/ice-repellent substance, or adding little heaters to the lights to melt the snow -- a little ironic, considering a regular light bulb could have done the job on its own before.
What's surprising is that the problem hasn't been deadlier than it's proven already, and that's probably because drivers are better than we might think about handling obscured lights. The rule at intersections where the lights are obscured is the same as that where the lights are out completely: Treat it as a four-way stop. The problem is what happens if the weather is so bad that you can't see the presence of the lights at all: Where before a driver might have had a hint of a stop ahead thanks to a dim red glow through the driving snow, now he may have nothing to cue him into it.
Save us, technology!
http://tech.yahoo.com/blogs/null/158097/when-leds-go-wrong-snow-covered-stop-lights/;_ylc=X3oDMTI1a210M2RpBFJfYWlk AwRSX2RtbgN5YWhvby5jb20EUl9maW QDYzZmMGRmYTY3ZWU3NzE5MjA4M2My ODIzMDViNDRmODIEUl9sdHADMQ--
When LEDs go wrong: Snow-covered stop lights
Fri Dec 18, 2009 11:45AM EST
See Comments (http://tech.yahoo.com/blogs/null/158097/when-leds-go-wrong-snow-covered-stop-lights/;_ylc=X3oDMTI1a210M2RpBFJfYWlk AwRSX2RtbgN5YWhvby5jb20EUl9maW QDYzZmMGRmYTY3ZWU3NzE5MjA4M2My ODIzMDViNDRmODIEUl9sdHADMQ--#see_comments) (13)
Buzz up!15 votes http://a323.yahoofs.com/ymg/null__17/null-302757133-1261154298_thumb.jpg?ym6PUYCDE VwA7l17 (http://us.lrd.yahoo.com/_ylt=AgFFqpVOJV7yQwJgLgBMJg3PM ZA5/SIG=12qsg6o6o/**http%3A//a323.yahoofs.com/ymg/null__17/null-302757133-1261154298.jpg%3Fym6PUYCDEGoh8 5VP)Yay for power savings: Putting LEDs in stop lights means that intersections around the country use less energy to keep those red, green, and yellow lights burning 24 hours a day. By some measures, LCD lighting uses 90 percent less energy than incandescent lighting does, and the bulbs last much, much longer before burning out (thus requiring less manpower to constantly replace them). The bottom line is that it all adds up to significant savings for municipalities when spread out over many years.
It all sounds fine and dandy... but a catch is now becoming evident. Because LEDs don't get hot, they can't melt snow (http://news.yahoo.com/s/ap/20091215/ap_on_re_us/us_snow_covered_stoplights;_yl t=Atf.iYYyjYEEZqAcZSLrmvbPMZA5 ). Why is this important? Because in wintry climates, traffic signal alcoves regularly fill up with the white stuff, obscuring the lights behind them. Result: Drivers don't see red lights, and sometimes they plow through the intersection in their obliviousness. At least one driver has likely died as a result of snow-obscured traffic signals, and probably more.
The fix, for now, is decidedly old-school. After heavy snowfall, crews roll out to each intersection and clean the snow out by hand. It's labor-intensive and expensive... and it probably negates a large portion of the cost savings from using LEDs to begin with.
Now the hunt for a tech fix is underway -- whether that means adding weather shields to lights, coating them with a water/snow/ice-repellent substance, or adding little heaters to the lights to melt the snow -- a little ironic, considering a regular light bulb could have done the job on its own before.
What's surprising is that the problem hasn't been deadlier than it's proven already, and that's probably because drivers are better than we might think about handling obscured lights. The rule at intersections where the lights are obscured is the same as that where the lights are out completely: Treat it as a four-way stop. The problem is what happens if the weather is so bad that you can't see the presence of the lights at all: Where before a driver might have had a hint of a stop ahead thanks to a dim red glow through the driving snow, now he may have nothing to cue him into it.
Save us, technology!