Two weeks ago today, a few blocks from my home, a 5 year old girl named Allison was riding her bike through a crosswalk behind her father when she was killed by a driver. You can read her obituary here, and see a photo of her tiny ghost bike here.

In the time since, there has been a great deal of public outcry about road design, and a corresponding amount of attempts to derail progress on street safety by calling this “just a tragic accident.” In my own rage and fear and grief, I went on a bit of a tweetstorm about it, reproduced below.

A thing I need people to understand is that systems are optimized to produce the output they actually produce, and that this FREQUENTLY differs from what people THINK the system is optimized to produce.

This applies to every kind of system.

If the system output is bad, like for example it produces trigger-happy cops, or COVID misinfo, or teens becoming Nazis, or children being killed by cars on their bikes, then something about the system is producing that result and that thing can be *identified and changed*.

Sometimes it’s not just one thing, and it’s frequently hard to identify and change because we are all also parts of the system we seek to change. But it can be done if you commit to making these systems visible.

What we must NOT do is treat these bad outcomes as quirks of a good system, freak accidents, or even as examples of a “broken” system. It is not broken. It produces the outcome it produces. If you don’t like the outcome, change the system.

And yes, humans make choices within and as part of these systems, but we are not as advanced and rational as we like to think, and frequently it’s easier to change our behavior by altering the inputs we get than by just explaining to us why we should behave differently.

That’s why we need physical traffic calming instead of just more cameras and higher fines. It’s why we can’t train our way out of police shootings. It’s why monitoring your kid’s YouTube usage is good, but not algorithmically promoting Nazis is better.

The web services we use, the built environment we interact with, the forms of transportation we use, the institutions our society uses to maintain itself… all of them are choices. None of them are laws of nature.

If you don’t think about these problems systemically, then every police shooting is “one bad apple” & everyone killed by a car is “a tragic accident” & every radicalized white boy is “parents who should have paid more attention” and we will cluck our tongues as the world burns.

Originally tweeted by Tiffany Bridge (@tiffany) on September 15, 2021.