Are your schools connected directly to highways or something?
Roads are typically 2 lanes one in each direction. You already know this because you said a solution would be to remove the lane marker.
So you have a road with an elementary school, and 2 miles further down is a middle school. Even without that you have buses passing each other during pickup because busses only pickup kids on one side of the street so you don’t have young kids crossing roads. So one bus runs in one direction down a road picking up kids direction down the road.
We don’t have blocks.
What do you call a section of inner city bounded on all sides by a road in your country?