The Swedish towns of Ardala, Skara, Axvall and Varnhem are connected by a 20km bike path. It's fine to ride during the daytime. However, long stretches of it are unlit and pitch black at night.
The Skara municipal government calculated a cost of 8 million SEK (USD $771,356) to install lighting on a 10km stretch. That's outside their budget, so an alternative solution was needed. Incredibly, what they came up with is a system of drones each boasting two LED lamps that put out 32 watts total. You summon one of these lighting drones via an app, then they find you, and follow you as you cycle!
The difference between having your own bicycle headlight, versus the path being lit by a drone, is stark:
The drones are autonomous, but laws have yet to catch up. "Everything already works automatically today," Sweden's SVT News reports, "but the law still requires that there are drone pilots on site who supervise the drones. In the long term, the researchers expect this legislation to change."
The innovative initiative was created in collaboration between the municipality of Skara, Swedish research institute RISE, the University of Skövde and Jönköping University.