It's clear, now, that Google's driverless cars are a real thing.

Using a combination of extremely detailed maps, a quiver full of sensors, and sophisticated machine learning techniques for seeing the road, a computer-driven car can navigate most driving situations with ease.

But what about the unexpected? It's the first objection to driverless vehicles that most people come up with.

The Atlantic Cities got to go on a ride-along in a driverless car through the city (well, town) streets of Mountain View.

As they were bopping along under autonomous control, the car encountered some unanticipated roadwork. Here's what happened:

We are in the left lane on Mountain View's West Middlefield Road when some road work appears up ahead. A dozen or so orange cones guide traffic to the right. The self-driving car slows down and announces the obstruction — "lane blocked" — but seems confused what to do next. It won't merge right, even though no cars are coming up behind us. After a few false starts, Brian Torcellini takes the wheel and steers around the cones before reengaging auto mode.

So, for now, humans still have a purpose behind the wheel. But check out the rest of Eric Jaffe's article to see how long that might last. (Spoiler: not very long!)

Despite Google's engineers taking control of the car twice in a relatively short drive, the sense that the driverless vehicle's time has nearly arrived is palpable in Jaffe's story.