One you see half-naked guys ruunning in their underwear around town in August you can be sure that the new academic year has started. That's just one of the rituals they have for their freshmen.
Another sure sign that the new term at NTNU has started is a traditional maritime race across the river Nidelva in improvised “boats”. That is, teams from each Faculty and Department are building improvised floating objects and their aim is to keep on the water surface for the longest period of time. If they even succeed to reach the other bank of Nidelva than they win.
Not only that the floating objects are unstable (and sometimes don’t float at all), but the teams make ih a hell for other teams by throwing waterbombs and gasbombs that makes this event a really colorful sight on the river that you shouldn’t miss if you happen to be in Trondheim in September.
Trondheim has the largest population of students per capita than any of the Norwegian cities I know.
This of course does show itself. The most used method of transportation is the bicyckle. The bike is also used in the winter (usually with winter tyres: Spikes).
You'd better wach out for those bikes!