That's fairly contrived. Schools are already very segregated by affluence and buss routes need to handle every student outside of walking distance.
So, the net result is mostly just empty buses, and wasted gas.
So, the net result is mostly just empty buses, and wasted gas.
OTOH though, we have elementary schools in urban/suburban areas where 1/2 of the population of the school falls within the 2 mile radius (great saves money on busing!). Combined with high speed traffic, questionable neighborhoods, bad weather, a tendency towards overprotective parenting, and most parents of early elementary school children are going to be driving them rather than letting them walk to school.
The crazy thing is that most elementary schools are going to be getting out at ~3PM, which is far to early for most parents to leave their jobs, which means they end up paying a few hundred dollars a month per child in after school fees. A real problem for people near the poverty line, so those are the 5 year olds you see walking home alone at 3PM...
The school isn't built like a sports arena, so traffic flow around it is fine throughout the rest of the day, but morning dropoff in particular is very congested because the volume of traffic spikes for a single 15 minute period each day.
Coupled with general morning rush hour traffic, this ripples out to long left-turn waits (no turning arrow), congestion, angry drivers trying to cut down residential streets, parking problems, and so on. Then depending on how far away you had to park, you have to walk that distance with young kids.
Pick up time is easier, especially with after school programs, because the spike is diffused out over a wider range of time.
I can only suggest this is the kind of thing that's generally fixable by a local community.