Change Your Course
I've found that this year SO many classes are running over by 5 minutes or more, which is fine if you're going from one part of commons to another, but a lesson in Newton to a lesson in Commons takes much longer. I've been later to a fair few lessons already and it's only week 4. This is mostly due to clocks all over commons being a few minutes out on either side. Thus, several lecturers are working out of sync with class times. I know that people who work on campus have been late to work a fair few times, and several of us have rocked up in to lessons after they've already started.
If there was a universal way of signifying the end of every lesson at 10 to the hour (a bell, or just amended clocks in every room) , it may just make people's days run slightly smoother and make everyone a little bit more on time.