The municipality of Hole, in Norway, is testing the new, energy-saving technology on a nine-kilometre stretch of road less than an hour’s drive west of the capital of Oslo.

When the road is empty, the lights operate at about 20 per cent brightness. When radar sensors (there’s one on each of the 220 light poles on this particular section of route 155) detect oncoming cars, cyclists or pedestrians, the lights ramp up to full brightness.

This isn’t Norway’s first test of auto-dimming street lights, but it is the largest. And while we’re not sure of the cost of this latest pilot project, Norway’s public roads department says the high-tech lights could bring big savings on low-traffic roads.

The government estimates the technology could cut energy use by up to 80 per cent on this particular road and pay for itself in about 4.5 years; the equipment has an expected lifespan of 15 to 20 years.

Another benefit of such street lighting is a potentially significant reduction in light pollution.

Check out the lights in action thanks to YouTube user Bjørn Nyland, whose video we’ve included below. Note that he rhymes off a number of facts about the lights, but doesn’t say where he got his information.

(Via (In Norwegian))