I often hear that the lights are timed. I've never encountered a street where they were timed.

I've certainly seen it in places... There's routes I drove where if you had a green and you keep within narrow speed ranges, you get greens, and if you go at the inbetween speeds, you get reds. Some of those might not be 100% consistent if something interrupts the regular cycle like a pedestrian crossing or an emergency vehicle.

Otoh, Milwaukee circa 2003 had all the lights on a schedule. Every intersection made the same changes every day. Super frustrating when I was consistently slow to get out of the house for a scheduled pickup and missed the light everytime.