UPS has successfully tested a drone that launches from atop one of its package cars, the company announced. The system is designed to autonomously deliver a package while the truck is driven on a route.

The drone can autonomously deliver a package to a home and return to the truck while a delivery driver continues along the route to make a separate delivery.

The test was conducted in Tampa, Fla., with Ohio-based Workhorse Group, a battery-electric truck and drone developer. Workhorse built the drone and the electric UPS delivery truck used in the test.

“This test is different than anything we’ve done with drones so far,” said Mark Wallace, UPS senior vice president of global engineering and sustainability. “It has implications for future deliveries, especially in rural locations where our package cars often have to travel miles to make a single delivery.”

Rural delivery routes are the most expensive to serve for UPS due to the time and vehicle expenses required to complete each delivery. A reduction of just one mile per driver per day could save UPS up to $50 million in a single year, according to the company.

If implemented, the drone can aid drivers at various points along a route to help save time and reduce costs. The drone docks on the roof of the delivery truck. A UPS driver can load a package into a cage suspended beneath the drone through a hatch built into the truck. The driver can then direct the drone along a preset autonomous route to the address.

The done in the test was a Workhorse HorseFly UAV Delivery system model. It has a 30-minute flight time and can carry a package weighing up to 10 pounds. The drone recharges in between flights while it is docked.

“Imagine a triangular delivery route where the stops are miles apart by road,” said Wallace. “Sending a drone from a package car to make just one of those deliveries can reduce costly miles driven. This is a big step toward bolstering efficiency in our network and reducing our emissions at the same time.”

The drone in the test was loaded with a preset route but in the future, routes could be determined by UPS’s On-Road Integrated Optimization and Navigation, which is the company’s proprietary routing software.

“It’s wonderful to see this technology applied in such a practical way,” said Stephen Burns, Workhorse founder and CEO. “The drone is fully autonomous. It doesn’t require a pilot. So the delivery driver is free to make other deliveries while the drone is away.”

Watch a video of the drone test in action below: