HOUSTON -- You're not supposed to think too much about traffic signals, but you notice them when they're gone. 

After the hurricane, city workers reached out and touched almost every single signal. And now, the city of Houston is about to do it all over again.

The Public Works Department wants to spend more than $16 million replacing every bulb in every light with new, high-efficiency L.E.D. bulbs. It's already happened downtown and in Midtown.  But soon it will expand citywide

This is all because the current lights use up electricity at an alarming rate.

"Aggressively our guys are looking at somewhere around December of next year to have them finished," said Alvin Wright, Houston Public Works

Houston is not the first city to try this. An experiment in Little Rock, Arkansas, revealed that the old light bulbs cost $2.75 each, while the high-efficiency ones cost $60 bucks. But normal traffic signals use 135 watts, and the LED's use just ten.

This means they are cheaper to operate. The city estimates the new bulbs will eventually save taxpayers $10,000 a day.

The city promises that changing all the light bulbs won't be as disruptive as it was following Hurricane Ike. The main reason is because this time the city can plan ahead.