In A Certain Scientific Railgun, it's mentioned several times that there is a curfew for students in Academy City. Why is this so? Is this ever explained?
Some schools within the city are like most boarding school have curfew's for their students. Tokiwadai being a prestigious all girls school has a particularly strict one, reasoning being girls shouldn't be out late. Not all schools have them it seems. Judgement act is similar authority as prefects for people and students within the city.