Apostrophe errors please help?

At community colleges, students' cars often outnumber available parking spaces. It's a problem shared by many of the country's best schools. What's a campus to do? Some schools use off-campus lots as a solution, but they're often the cause of a new problem-security. When a student's away at cl, who's protecting the students car? A greater concern involves everyone's physical safety because some students have to walk to and from the main campus at night. That's why all police cadets' duties include escorting night students to these lots. For these reasons, most people agree that the remote lots parking fees should be much lower than the ones on campus. However, the decisions in these matters were not the students' decisions, but the administrations. Even though the students' cars were the vehicles that would be affected in the 1970's when the community college was built this was not a problem.