system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: In cities with grid layouts, why aren't traffic lights synchronized so that all lights on parallel roads turn green and red at the same times.

For example, all streets that run east/west would be timed the same and opposite from those that run north/south. Seems like this would help reduce gridlock.
gpt
Stop lights are timed according to complex studies by transit authority to provide the best traffic flow that causes the least amount of accidents. Science has shown that for the most part that means a "ripple" type cascade of the lights turning in a given direction works better than all lights in that direction going green at once.