Self-driving automobiles like the one Google is working on remain pretty mysterious, as few have seen the prototypes that Google is testing on California’s roads. So it is perhaps not surprising that a national newsmagazine like Time would print an article based on the account of an anonymous witness, who says they see Google cars every day, and has some observations to share.

The witness says they live in Mountain View, California, where they reportedly see up to six of the modified Lexus vehicles every day while riding their motorcycle. Though the witness, who wrote a post on a technology blog, mostly had positive things to say about riding near the self-driving vehicles, they did say that the cars “drive like your grandma.”

In other words, the vehicles typically act more cautiously than human drivers. For example, the blog post described the cars being slower to accelerate when a light turns green. The cars also tended to slow down a great deal at intersections with low visibility, perhaps more than a human driver would believe is necessary.

This is supposed to be one of the big selling points of automated vehicles, of course. They are supposed to eliminate the risk of a human behind the wheel who is drunk, distracted, experiencing road rage or is simply reckless. The witness’ post noted that the Google cars never speed or cut people off when changing lanes, maneuvers that often lead to car crashes when human drivers do them. The writer said they felt safer around the Google cars than being near “most California drivers.”

Perhaps more and more of the glimpses will come to light over the next several years, as Google and its competitors continue to refine their cars.