For one and a quarter miles along the E16 highway in Sweden, north of Stockholm, the air above the road crackles with electricity. Using a catenary system similar to that used for trolleys, two diesel-hybrid trucks will drive cargo back and forth, as a trial case for low-emissions shipping. If successful, the system could be an easy way to adapt existing roads into greener, electric pathways.

Says Siemens, one of the companies operating the system:

The trucks can drive as fast as 55 mph while connected to the system, and because they are hybrid trucks, they can still deliver to places not connected to the electrical supports overhead. Which is good, because the trial system is, again, tiny: a 1.25-mile stretch of one highway.

There are plans for future tests. Working with Volvo, Siemens plans a test of a similar system spanning the ports of Los Angeles and Long Beach.