Super Bright LED diodes-

Ever see those traffic signs that use dozens of LEDs instead of an incandescent bulb. Well you should expect to see them more and more. As of Jan 2006 the government imposed a maximum wattage the traffic signal could use, 17 watts, which is much less that a comparable 130 watt incandescent lamp. Many of the traffic signals were traded out years ago

These Bright LED modules cost more than there incandescent counterparts, but also last ten years instead of the two years for incandescent's.

Energy Policy and Conservation Act.
Any traffic signal module or pedestrian module manufactured on or after January 1, 2006, shall meet both of the following requirements:
(a) Have a nominal wattage no greater than: [only higher wattage for 74C is shown]
12" Red Ball ........................................... 17 watts
8" Red Ball ............................................. 13 watts
12" Red Arrow ...................................... 12 watts
12" Green Ball ....................................... 17 watts
8" Green Ball ......................................... 13 watts
12" Green Arrow .................................. 12 watts
Combination Walking Man/Hand ...... 16 watts
Walking Man ......................................... 12 watts
Orange Hand ......................................... 16 watts
(b) Be installed with compatible, electrically connected signal control interface devices and conflict monitoring systems.

Pedestrian module means a light signal used to convey movement information to pedestrians.
Traffic signal module means a standard 8-inch (200 mm) or 12-inch (300 mm) traffic signal indication that—
(1) Consists of a light source, a lens, and all other parts necessary for operation; and
(2) Communicates movement messages to drivers through red, amber, and green colors.

LED light sources for traffic signals offer significant energy savings over incandescent lamps. LED signals also last much longer than incandescent signals (7 to 10 years instead of 2 years) and fail less frequently. The additional benefit is the reduced power consumption (10 to 22 Watts) for LED bulbs compared to the typical energy consumption of incandescent bulb (135 Watts); the savings from the low energy use of LED signals can be 80% to 93% and will help reduce greenhouse gas emissions.

... If all of the three million traffic signals in the United States were converted to LEDs, some three billion kilowatt-hours of electricity would be saved annually ..... Electricity is generated by coal or nuclear plants, so oil imports aren't effected.

You can also find these bright LEDs in flash lights and in normal 'light bulb' configurations [Edison Screw Base]. However many still insist that fluorescent bulbs provide a better alternative to an incandescent bulb. The amount of light given off and it's relative color are two reasons why a Super Bright LED lamp does not fit well in some in-door light applications. LED bulbs also cost more to operate than fluorescent bulbs.