For many students who live in South Brookline, getting home after school is no small task: Living four or more miles from the school, they must take the Massachusetts Bay Transportation Authority (MBTA) supplemental 51 Bus, which is a special route that picks up high school students on campus after school. According to students, the bus is problematic due to its tardiness and inconsistency in arrivals, however, administrators said that they can’t do much about it because the bus is operated and run by the MBTA.