The biggest threat to self-driven cars is human-driven cars.

By the year 2020, you will have done this.

As nice a person as you are, you know you will.

A car pulls up opposite yours at a 4-way stop. It gets there half a second before you do.

It has the right of way. You know it, and it knows it.

But you can see that there is no human behind the wheel, and there is no wheel. It’s a self-driver.

The people inside, busy texting. Nobody else around.

You let the robocar crawl cautiously into the intersection, watching as it checks all directions like a kid taking a driver’s test times a digital million.

It begins to accelerate — and that’s when you take off at approximately the speed of light, and turn left right in front of it inches from impact.

The robot car slams its brakes on, as it is programmed to. You complete the turn, and toddle off.

The texters inside the other car are now wearing their lattés.

“Follow that car!” one passenger yells, as if this is a 1945 movie and he is Jimmy Cagney.

But the car does not follow you. It continues on its way. The gestures the passengers fling at you are somewhat diminished by the fact that they are expressed through the back window of a car now driving like grandma at precisely the speed limit in another direction.

You are human.

It is programmed to receive.

We are all bullies now.