One of Google's self-driving cars. AP Google's self-driving cars are very careful.

When Google released its first accident reports in June, the company revealed that in the combined 1.8 million miles its cars had been on the road, they had been involved in 12 minor accidents, none of which were their fault.

But this default to caution can cause strange incidents when Google cars run into humans engaging in nonstandard behavior.

One such incident reportedly occurred earlier this month in Austin, when a robot car was baffled by a man riding a fixed-gear bike — aka a fixie, a favorite of so-called hipsters around the world — The Washington Post reports.

Here’s what happened.

The Google car and the cyclist both arrived at a four-way stop.

The car got there a fraction of a second before the bike, and the cyclist says he waited for it to continue through.

But instead of just putting a foot on the ground at the stop sign, the cyclist did what's called a trackstand.

A trackstand, common among fixie riders, involves the rider pedaling both forward and backward while trying to stay upright and moving a minimal distance.

This GIF shows a rider on a fixed-geared bike doing a trackstand:

YouTube/iSteezy

The issue is that, during such a trackstand, the rider does usually move slightly forward or backward — at least enough to alert the conscientious Google car that some human might be blasting through the stop sign.

“It apparently detected my presence,” the cyclist writes. “And stayed stationary for several seconds. It finally began to proceed, but as it did, I rolled forward an inch while still standing. The car immediately stopped … I continued to stand, it continued to stay stopped. Then as it began to move again, I had to rock the bike to maintain balance. It stopped abruptly.”

The car just could not make up its mind as to what this cyclist was doing.

A cyclist on a fixed-geared bike, aka a fixie. Flickr/Bilobicles Bag

“We repeated this little dance for about two full minutes and the car never made it past the middle of the intersection,” the cyclist writes.

But even though the car’s behavior was strange, the cyclist says he felt safer dealing with it than a human-operated car.

In a recent survey, 27% of Americans said they would support laws restricting human drivers and favoring robot cars in the future.

Perhaps cyclists, who routinely face unsafe human drivers on the road, might lead the charge.

For its part, Google says it is trying to take cyclists seriously. The company has patented a method by which self-driving cars can identify cyclists and understand their hand signals.

Though Google still hasn’t answered the question of why hipsters love fixed-gear bikes so much.