A battle is brewing on how best to tackle the last mile conundrum as it relates to package delivery – that is, finding the best or most efficient way to transport a package from a nearby hub to a consumer’s front door.

Major players like Amazon, Google and UPS seem dead-set on tackling the matter via aerial drones although those have already proven unreliable if weather conditions aren’t ideal (not to mention all of the legal red tape that still exists). Perhaps the best solution may be a ground-based approach like that of Starship Technologies.

As we profiled late last year, Starship has developed a fleet of six-wheeled autonomous robots designed specifically to handle last-mile package delivery. These robots would be based at a nearby hub and deliver packages within a small radius.

But what if there’s no hub in the immediate vicinity? That’s where Starship’s partnership with Mercedes-Benz comes into play.

The two have developed a prototype “Robovan,” a mothership of sorts for Starship’s delivery bots. The mothership is simply a Mercedes-Benz Sprinter van that’s been outfitted with ramps that allow the bots to easily enter and exit. In the rear are several cargo bins filled with packages to deliver; the van’s driver is responsible for loading each robot with its cargo before it goes out into the world to complete delivery.

If you’ve seen an accessible minivan that has been modified for wheelchair users, you’ll be somewhat familiar with how the ramp system works. Each van can accommodate up to eight Starship robots. According to Starship, this system can allow for up to 400 packages to be delivered in a nine-hour shift.

Starship has already conducted limited trials in London with plans to expand across Europe in the near future.