ASTC systems do not "dramatically reduce congestion." They result in a small (probably single digits) increase in traffic flow at best, which is a rounding error. God, I'm sick of this dude's flyover videos and him being treated like some genius.

Numerous cities don't bother with ASTC systems because they a)don't do very much yet cost a lot of money in equipment and staffing, and b)just further incentivize low occupant vehicle traffic, which is just about the lowest priority in most cities these days because that in turn creates more traffic. If there was one overarching tenet to traffic engineering and urban transportation planning, it's that you cannot solve traffic by building more roads. It doesn't work. It has never worked.

Traffic is something 99% of the population thinks they understand because they sit in it, see it, etc. and probably 95% don't have the foggiest idea how it actually works, and merely have a severely uneducated and highly biased personal opinion. And boy howdy, do they hate bike lanes and bus lanes.

Adding (or removing) a lane does not even remotely have a direct correlation to maximum traffic flow. If you have a three lane road and you make one lane a bus or bike or bus-and-bike lane, you do not lose 1/3rd the traffic flow capacity. It's dramatically less than that.

By making bus transit faster (where each bus holds ~60 people...) and biking safer, not only do you actually reduce traffic, but you also provide emergency vehicles with a faster route through traffic.

In Paris more people travel by bicycle than car. That was a direct result of Paris heavily restricting motor vehicle traffic through the center.

Every person on a bicycle is one less person causing noise, pollution, congestion, wear to the road, danger to others, and using (at least) one less parking space (because you don't just need a place to put the car where it is kept, you also need space for where it is going.)

Simcity designers initially based Simcity off actual real-world stats and planning figures. They had to throw out the figures for parking and road capacity because otherwise the game would have looked like nothing but roads and parking lots.

What I find most interesting about the computer side of traffic signal controllers is the interlock design needed to prevent a glitch or memory fault from activating conflicting phases at once, eg two intersecting approaches getting green simultaneously. That's about as safety-critical as it gets for a piece of everyday infrastructure. Would've liked to see more depth on that, though I imagine the specifics are controller/vendor-specific.

I think that interlock design also goes some way toward mitigating the security risks ASCT systems would otherwise pose, as mentioned in the article. On any decent controller, even the control room shouldn't be able to deliberately trigger conflicting phases.