Germany is trialling a new highway that uses overhead electrified cabling to recharge the batteries in hybrid vehicles as they drive, reports Business Insider. The Siemens-developed eHighway is designed to work with a custom Scania hybrid truck developed by VW Group. Germany’s pilot of the technology is currently operational on a six-mile stretch of autobahn near Frankfurt and is set to run until 2022, after which it could be expanded more broadly across the country.

The eHighway works by delivering 670 volts of DC power to a truck’s “pantographs” or conductor rods. The system only works at speeds of less than 56 mph, but while in use it means that the hybrid vehicle can run entirely on its electric motor while simultaneously charging its battery. At the end of the electrified segment of road the truck can continue to draw from its batteries, switching to its diesel engine when they’re fully depleted.

A stop-gap to fully-electric trucks?

This isn’t the first time we’ve seen a company attempt to dynamically charge an electric vehicle while it’s being driven. Siemens’ eHighway technology has already been trialed and demonstrated in Sweden and California respectively and Sweden has also installed underground rails on one road that can recharge cars. Trolleybuses, buses that charge from similar overhead cables, are also still used in hundreds of cities around the world.

Siemens claims that its eHighways can save a 40-ton truck €20,000 in fuel costs over 100,000 km of driving. However, in the long-term, fully electric trucks such as the Tesla Semi could theoretically save far more by going fully electric. They also wouldn’t have to stick to specific electrified lanes on specific highways that are equipped with ugly overhead power lines. The only problem, as with all electric vehicles, is getting enough range.