Walking down the red hallway in the middle of the day might as well be the same thing as walking through a mine field, a minefield of sitting students waiting to be stepped upon.  During lunches, students are allowed to eat in the courtyards, or along the walls in the hallway, but it has become so overcrowded that it hinders the waling of others

First off, there does not need to be groups of eight people sitting on the ground eating lunch because eating lunch in the hall is for those small groups who want to get away from the clamor, but if there is a group of eight then they could easily have a table to themselves.  These numerous amounts of hallway eaters also cause other disturbances such as leaving their trash on the ground.  While it is understandable that most students leave their trash on the ground after they eat, but certainly not acceptable, regardless, at least they are in the cafeteria where all the food is concentrated anyway and it is easier to find and pick up and the custodians do not have to hunt the halls to find the trash.

Another issue it causes is disturbances to classes.  Due to the large amount of people who eat lunch in the hallway, it gets almost as loud as the cafeteria and there are classes nearby that hallway that can be distracted by the noise.

Also, after they are done eating they get up and roam the halls, which is not really allowed but everyone does it, and continue to spread their trash throughout the school and manage to optimize the amount of classrooms that they can disturb.

The answer is simple: just eat in the cafeteria. Unless it is just you and your friend seeking some peace and quiet, if you have a large group just sit at a table.  Hallway eating should not be banned, but merely regulated so that everyone can enjoy it.