Scholl drop off
1.30 finish for younger kids
2.30 finish for older kids
Thats 3 times a day
If it's a secondary school, they all get out at the same time, so it's just twice a day.
OP didn't specify which type of school it is. But at most, if 20 minutes at a time, it's a maximum of just one hour comings and goings out of 24 hours in a day, on only about half the days in the year.
Some people - such as OP and neighbours - see that as a problem. Personally, I don't. But we've moved on from that part of the discussion anyway.