21ST CENTURY HEADLINES: I was behind the wheel when a self-driving Uber failed — here’s what happens.

I was driving on a perfectly straight back road, pictured below, without any cars when I heard a ding indicating the car wasn’t driving itself anymore. The engineer in the passenger seat wasn’t sure why the car stopped driving.

When the car goes back into manual mode, it doesn’t automatically stall, but begins to slow down. That means you have to be aware the entire time you’re behind the wheel in case you’re on a road where there are cars around.

When I was riding in the backseat, the car switched into manual mode on a busy bridge. Our driver had his hands on the wheel the entire time and took over so quickly you wouldn’t have known anything had happened had a noise not sounded. We were told the failure had nothing to do with being on a bridge, but with how busy our surroundings were.

There are also situations where drivers are advised to take over, even if the car doesn’t switch to manual mode.

For now at least, I’d prefer to take over whenever the engine is running.