if you always obey pedestrian lights and never cross when it's red but there's no cars, why?
that's the norm you grew up with everyone following
you don't want to set a bad example to kids
scared/intimidated by roads or can't tell/not confidant when there's no cars
don't want to be judged for breaking the social rules
multiple/other
don't avoid crossing when there's a red light but no cars
results
I picked not confident but would like to elaborate that, even when I'm sure there are no cars, I know that sometimes I dissociate while walking and lose a good sense of my surroundings, and it's helpful to maintain a habit that I fall back on when I'm running on autopilot.
there's this concept called "rule utilitarianism" that means following rules even when the reason for following them is not immediately present. it's not a universal ideal, but very good for situations like safety practices, which includes most traffic laws.
stopping at stop signs even when there's no traffic in sight and not pulling forward onto a train track before the car ahead of you moves far enough forward to give you space to get off the tracks again are more intuitive examples of this practice.
basically, what you'd be doing if you cross against the light is you're loading onto yourself all of the liability in case you've judged the situation wrongly.
in driving, people often say that consistency matters more than courtesy. things like yielding when you have the right of way may feel nice to do for someone, but it is confusing to everybody else on the road and adds to the mental load of other drivers by interfering with the predictable behavior that everyone uses to navigate the complex situation that is navigating the shared space of roads and intersections.
people also have, let's say, varying, abilities to judge the situations in front of them well. one person's "there's no cars at the intersection" is "no cars are in sight" and another person's is "there's cars but they're a ways away" and another person's is "they're coming but I can make it if I run" and another person's is "eh, they can avoid hitting me." more and more people doing this is more and more opportunities for bad judgment to turn into tragedy, and of course more situations where a driver with the right of way has to navigate pedestrians being where they're not supposed to be, which is nerve-wracking.
there's places where there are a lot of pedestrians wandering around and drivers have to be more alert to avoid hitting them, such as parking lots, but nobody would like for that experience to be expanded to include all roads. nobody wants to have to stop on green because some optimistic pedestrian has decided to play Frogger. nobody wants their commute time to increase by a third because the flow of traffic is interrupted by regular pedestrian incursions against the light. nobody wants to sit and wait in traffic more often while emergency vehicles converge on a spot long enough to shovel up chunky salsa that used to be a person, which gets both more likely and more unpleasant the faster the traffic that person tried to dodge is.
traffic is a system and it runs on rules, many of which involve questions of who has the right of way at a given time. people deciding to write their own exceptions muck up the system, making it less efficient and more expensive for everyone in time, cognitive load, and property, lives, and emotional well-being.
traffic sucks. being a pedestrian stuck at a traffic light sucks. there's temptation to shave some time off of that when the opportunity beckons, or seems to beckon, or usually beckons and someone's on autopilot. but obeying traffic rules, including Don't Cross Right Now, is the minor nuisance that is the price of avoiding the major nuisance of traffic, including pedestrian traffic, being a thousand times worse.
