The world’s first electrified road — which charges the batteries of electric cars and trucks as they drive over it — has opened near Stockholm, Sweden. The road stretches 1.2 miles and is part of a government-led plan to electrify nearly 12,500 miles of streets and highways across the country, The Guardian reported.

The road charges vehicles through an embedded electric rail. To use the road, an electric car or truck needs to install a moveable arm on its undercarriage that connects with the rail and charges the vehicle’s battery while driving over it. The system costs $1.2 million per kilometer, making it 50 times cheaper than building an urban tram line.

The developers of the road say the technology helps eliminate the need for roadside vehicle stations, which can delay travelers while they wait for their vehicles to charge. It also means car batteries can be smaller since they wouldn’t have to store as much charge, which would help cut battery and manufacturing costs.

“There is no electricity on the surface,” Hans Säll, chief executive of the eRoadArlanda consortium behind the project, told The Guardian. “There are two tracks, just like an outlet in the wall. Five or six centimeters down is where the electricity is. But if you flood the road with salt water, then we have found that the electricity level at the surface is just one volt. You could walk on it barefoot.”