The color of white light is based on the temperature of the light source. LED's are able to make a hotter light but run it at a cooler temperature. The inherent design is less fragile as well. The fact it does all this with significantly less energy draw makes it that much more impressive. Where I live almost all the traffic signals have switched to LED's. Most new emergency vehicles are using LED lights as well. They are just better in all aspects. It's because of this and the fact that it's relatively new technology to the general public that it costs more. I would think that LED will be like digital TV, and will phase out the older type.