A whole host of startups have launched in recent years with the aim of making last-mile deliveries using robots. But a company from Michigan has a new spin on this familiar enterprise: it wants to put those bots in bike lanes, at least part of the time.

Refraction AI came out of stealth last week, unveiling its autonomous delivery robot REV-1 onstage at a TechCrunch event. The company’s co-founder and CEO Matthew Johnson-Roberson, a University of Michigan professor, described the three-wheeled vehicle as a “Goldilocks” solution to last-mile delivery robots — neither too big nor too small.

“lightweight, nimble and fast enough to operate in the bike lane and on the roadway”

REV-1 is larger than most delivery robots, which are about the size of coolers and drive on sidewalks. But it’s smaller and less expensive than autonomous delivery vans or shuttles. The robot is lightweight and low-power enough to “qualify under e-bike regulations,” says Refraction’s website, and at 32 inches wide it slots neatly into a bike lane.

“Our platform is lightweight, nimble and fast enough to operate in the bike lane and on the roadway,” Johnson-Roberson told Trucks.com. With a unit cost of around $5,000, the REV-1 will also be more affordable than bigger rivals, while still offering enough space to carry four packed grocery bags of shopping.

But while Refraction’s robot might be the right size for commercial customers, it could end up annoying the public. There have already been protests about the intrusion of delivery robots onto sidewalks, with some cities even banning the bots. Placing them in bike lanes could be even more disruptive, as well as potentially hazardous for cyclists.

“It’s a bit presumptuous for Refraction to claim they can operate in bike lanes. They would face a pretty big debate and permit process if they tried to operate in Portland,” Jonathan Maus, publisher of BikePortland.org, told Trucks.com.

Before that becomes an issue, though, Refraction has to deal with a much bigger challenge: the weather. The company is trialing its robots in Ann Arbor, Michigan, where it says it’s learning to navigate in rain and snow — something that most East Coast-based robot delivery startups avoid altogether. The firm hopes its hardy robots will set it apart.

“Other companies are not trying to run in the winter here,” Johnson-Roberson told TechCrunch. “It’s a different problem than the one that others are trying to solve, so we hope that gives us some space to breathe and some chance to carve out some opportunity.”