A pair of hospitals in the Swiss city of Lugano have been testing the use of drones to transport laboratory samples. Since mid-March, logistics company Swiss Post has operated more than 70 tests flights between the two hospitals, and announced today that it plans to establish a regular service by 2018.

This isn’t the first time we’ve seen drones used to transport medical samples. (Silicon Valley firm Zipline uses fixed-wing craft to carry out this task in rural Rwanda.) But Swiss Post claims it’s the first ever commercial deployment of drones in an urban area. Operating drones in towns and cities is particularly challenging due to the risk of civilian injury, but Swiss Post says it has been working with the country’s aviation regulators, FOCA, since tests began earlier this year.

Delivering medical packages has turned out to be a perfect use case for drones. The samples are lightweight, so they don’t overburden the aircraft, and delivering them is often a time-sensitive matter, worth the extra expense of using drones. In the case of urban deliveries like Lugano, the craft also avoid getting snared in city traffic — adding to speedy delivery times.

“The regular use of drones between the two hospitals will become an everyday occurrence,” said Swiss Post in a press release. “Trained hospital staff will be able to load the drone independently with a safety box (in which the lab samples are packaged) and launch the drone with a smartphone application. The drone will then fly autonomously along the predefined route to its destination, where the box will be received by another member of staff.”

The drones are made by American company Matternet, have a load capacity of up to two kilograms, a range of 20 kilometers, and a top speed of 36 kilometers per hour (10 meters a second). Infrared sensors are used to guide their takeoff and landings, and in the event of an emergency, the drones have a built-in parachute to ensure they fall safely to the ground.