Thanks for the comment and taking the time to read this, Steve. In many ways, traffic engineering is “wayfinding” — a term mostly reserved for architecture, but also used for urban planning. It is, indeed, design. And, one of my favorite things to do is study other design domains (like architecture, wayfinding, traffic engineering) to improve the way I approach interfaces in the health systems I design daily. A lot of times, I can find a concept that translates to an interface I am working on or will work on in the future.
If you really dig traffic and urban design, I would strongly suggest checking out 99% Invisible. They have a ton of articles and podcasts covering the topic. This is one of my favorites: Urban Crop Circle: “Ghost Roundabout” Designed to Confuse & Slow Drivers.