A heck of a lot of stop signs would become yields. A heck of a lot red arrows would become blinking yellow arrows.

We could probably do automatic speed limits on limited access highways by measuring the current traffic speed, hitting it with some sort of weighted algorithm to prevent swings in speed or comically high/low speeds.

Frankly I'm surprised there's no such thing as a "yield, unless you're turning left or going straight" type stop sign since there are a lot of intersections where that's what the prevailing traffic flow is in practice.

A ton of intersections could be redesigned to facilitate easier and safer jaywalking with carefully placed islands.

If I had to change the law I'd have stiff fines for stopping at a cloverleaf and I'd make failing to go the minimum speed (which is usually the speed limit minus some constant) subject to the same fine schedule as speeding.