The end of the age of interlocks

I used to write software for a machine with moving parts and high powered lasers inside. The designers made it turn off when the door was opened. They didn’t ask my software to please turn it off. Opening the door flipped a switch and cut off power.

That was a mechanical interlock. It was a simple device that was important for safety.

I agreed fully with their decision not to trust my part of the system. In our lab the computers did sometimes fire the lasers too long or grab something wrong. But not when customers’s heads or hands were inside.

When I went to park my loaner car, the one with the designed-to-distract touch screen, I couldn’t find a parking brake. Some exploration discovered an inch-wide flimsy plastic tab with ambiguous polarity. Do I push it to park… or pull it?

Whatever that tab did when pulled, it didn’t set the brake or lock the transmission. It asked the computer to please set the brake. Or did it ask the computer to release the brake?

We have two problems here, a bad user interface and a missing safety system behind it.

I had sudden brake failure once. The brake cylinder seals let go. The primary brake system was toast. All I had to to was press the parking brake pedal which pulled on a cable which set the brake. An end-to-end mechanical link. That was a 1970s station wagon. My 2004 sedan has the same system. If the ABS computer loses its mind and kills the brakes, I can use the emergency brake.

My car is the last generation of car you can stop in an emergency.

Toyota had some bad press a few years back when its cars started accelerating out of control. Why didn’t the driver turn off the key? There is no key. There’s a button that asks the computer to please turn off, which it won’t do in motion because that’s dangerous. Why not shift out of gear? There’s a lever that asks the transmission to please shift out of gear, which it won’t do at speed because that’s bad for the car.

This summer people are scared of the “trolley problem” — your car intentionally killing you for the greater good. That is the least of your worries.

The runaway Toyotas didn’t go all HAL-9000 on their occupants. They did exactly what their masters told them to do.

Problem is, their masters are the people who wrote the software and took out safety systems because computers are supposed to be better. Toyota’s people chose a remote control that sometimes didn’t work. GM’s people decided a plastic tab was just as good as a foot pedal.

You, the driver, are losing control. You shouldn’t have to negotiate with your car in an emergency. You shouldn’t have to debug its software.

We need real consequences when people die due to confusing user interfaces and software controls replacing safety interlocks.

What we’ll get is weak, inconsistent enforcement against whoever didn’t donate to Democratic causes (if she wins in November) or didn’t build cars in America (if he wins). The American companies will be too big to fail, like they were in 2008.

I don’t trust the lawsuit lottery. I really don’t trust NHTSA. I want real consequences.

I want executives in prison.  I want product managers hanging from ropes when their bad decisions kill somebody.

The opinions expressed in this post belong to the author and do not necessarily represent those of the National Motorists Association or the NMA Foundation. This content is for informational purposes and is not intended as legal advice. No representations are made regarding the accuracy of this post or the included links.

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One Response to “The end of the age of interlocks”

  1. tzx4 says:

    With on these points. The worst thing about automation is that somewhere some designer and engineer is deciding what they think is best for you, and it seems there are always exceptional circumstances where the machine/software is flat wrong.