New York City mayor Michael Bloomberg and Transportation Commissioner Janette Sadik-Khan recently announced plans to upgrade the city’s 250,000 street lamps from traditional bulbs to LEDs. The transition, said to be the largest LED retrofit in the country, should be ready by 2017 and will save the city and taxpayers $6 million in energy costs and $8 million in maintenance each year.

Bloomberg said LEDs are the wave of the future because they last a long time and use a lot less energy. True enough, many LED bulbs can last 20 years or longer before needing to be replaced. That’s a lot longer than the six year lifespan of existing high-pressure sodium street lights.

In addition to energy and maintenance savings, the LEDs will produce a whiter light that will help illuminate the city’s 6,000 miles of roads and 12,000 miles of sidewalks. If a recent rollout of LED bulbs in Boston is any indication, however, not everyone will be thrilled with the new light sources. Some residents complained the light given off by the LED bulbs resembles what you’d find from a floodlight.

New York and Boston aren’t the only cities switching to LED technology. Earlier this year, Los Angeles completed a rollout that replaced more than 140,000 bulbs with their LED counterparts.

LED lighting has already been installed along Eastern Parkway in Brooklyn, along FDR Drive and in Central Park’s pedestrian paths. LEDs have even found their way to the East River bridges, city officials said.