Delivery Drones Could Take Public Transportation To Help Conserve Battery Power

Reading that “delivery drones could take public transportation to help conserve battery power” sounds rather strange. But maybe it isn’t such a bad idea once it is considered.

How did this idea come about?

Researchers from Stanford University found a way for hundreds of drones to use public transportation, such as a bus or trams, in order to redesign how packages are distributed in cities.

The Potential of Drones

The potential is that such delivery could reduce delivery van congestion and energy usage while, at the same time, extending the distance a drone can travel to deliver a package, since it would only have to travel from the public transportation to the place of delivery.

This would expand drone deliveries greatly because so far drone delivery has been mostly in the suburbs. The reasons for this are partly due to the fact that urban centers have tight quarters, and thus many obstacles in the way of the path of delivery, and also because drones are still not permitted to fly freely in cities.

Researchers are hopeful that by using public transportation, the authorities will be more open to increasing a drone’s ability to fly in urban centers.

This team of researchers, at the IEEE International Conference on Robotics and Automation (ICRA) published the following online:

“Our approach strives to minimize the maximum time to complete any delivery. By combining the strengths of both, we can achieve significant commercial benefits and social impact.”

This new, unique approach means that the drones will catch a ride on the outside of buses and trams, and thereby reduce the limited travel capacity of drones at this time. For instance, DJI Mavic 2 is able to fly a maximum distance of about 11 miles round trip.

The Capacity of Drones

The system Stanford is proposing, has the capacity to handle up to 200 drones which would be able to deliver as many as 5,000 packages. The artificial intelligence (AI) network was designed for cities with up to 8,000 stops. Such experiments were conducted specifically in cities such as San Francisco and Washington, D.C. For context, the San Francisco Municipal Transportation Agency (SFMTA) covers an area of 58 square miles and the Washington Metropolitan Area Transit Authority (WMATA) covers an area of roughly 150 square miles.

In estimating the routes the drones would take, simulations did not take into account any physical infrastructure. Therefore, tunnels were not included, as the report relied solely upon data of bus stops and locations of drone package depots.

This idea that may sound unique at first, maybe isn’t so unique, after all. According to the researchers, this solution resembles “algorithms on-demand mobility services” which were developed in order to coordinate multiple modes of transportation, such as what Uber, Lyft, and other companies that have combined ride-sharing options with public transportation, such as electric scooters, and walking.

The authors describe the solution as resembling algorithms of on-demand mobility services developed to coordinate multiple modes of transportation. Like Uber, Lyft, or other companies that take a two-layered approach, by combining ride-sharing options with public transportation, electric scooters, bicycles, and walking, this also conserves energy.

How it Works

Researchers at the Stanford Intelligent Systems Laboratory (SISL) and Autonomous Systems Laboratory,

explain how it is anticipated to work:

“First, the upper layer assigns drones to package delivery sequences with a near-optimal polynomial-time task allocation algorithm. Then the lower layer executes the allocation by periodically routing the fleet over the transit network while employing efficient bounded-suboptimal multi- agent pathfinding techniques tailored to our setting.”

Assumptions & Considerations

This multi-drone approach makes several assumptions such as packages being acquired from any dispatch depot, drones carrying one package at a time, and drones recharging or replacing batteries at depots when there is enough time. Other considerations to keep in mind are issues such as delays and the best time to travel.

Further research is needed, according to these researchers, who point out:

“A key future direction is to perform case studies that estimate the operational cost of our framework, evaluate its impact on road congestion, and consider potential externalities, like noise pollution and disparate impact on urban communities.”


There is no reason that this two-layered approach to transportation, with its ride-sharing options, would not reduce delivery van congestion and energy usage, while extending the distance a drone can travel to deliver a package. In fact, these researchers, from Stanford University, estimate that using public transportation can increase a drone’s range up to 360% beyond travel with flight alone.

What at first might have sounded strange, does not sound so strange once it is seriously considered in detail. Since this two-layered approach strives to minimize the maximum time to complete any delivery, it makes a lot of sense.

Khari Johnson@Khari Johnson, “Stanford lab envisions delivery drones that save energy by taking the bus” (June 3, 2020)

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