Most CS degrees have students do a "traffic light" exercise at some point: build an model of an intersection, run the stoplights.
Those lessons sometimes ask questions like "Are there pedestrians in your model? Maybe bikes? How about buses? Exactly who lives in the neighbourhood, do they relies on public transit? Et cetera.
A question I like to ask students, that always gets a lot of uncomfortable silence is: at what point do these decisions stop being software, and start being public policy?
I think there an extention to this, if the traffic lights are represented by 5mm leds, then a pedestrian crossing / crosswalk, needs red / green 3mm leds and a button so you press the button and the lights eventually go to red, and the 3mm green comes on. In a further extension, you can build 2x traffic lights to represent a intersection so that there are lights for different directions.
At some point this gets a little complex, but yes, it is a good exercise.
