In season8, episode12-The One Where Joey Dates Rachel, you can see Ross meets the problem.
Ross:- Guess what happened in the paleontology department today. Professor Newman, the department head, is retiring, so...
Rach:- They made you head of the department!
Ross:- No. I'm teaching his advanced class!......Why didn't I get head of the department?
(In class room)
Ross:- Oh, Does anyone know where the Freeman Building is?
A student:- Yeah. It's the new building on Avenue A.
Ross:- What? That's hole way across town. I'm supposed to teach a graduate seminar there in 10 minutes.
A student:- Dude, that's not gonna happen.
Ross:- OK. Move it! Move it! Move it! (in front of bunch of students) Hey! I'm the teacher!
(after a while)
Ross:-(breathlessly) Hello......Sorry I'm a little late, a- Whoa, a lot late. Well, let me start by introducing myself. I'm Professor Geller. (the bell ring) So to sum up... I'm Professor Geller. Good job today.
(after a while in coffee shop)
Rach:- You were 50 minutes late to class? What did you crawl there?
Ross:- No, I ran, okay? It's really far. When did people stop understanding the phrase" Get the hell out of my way"?
Rach:- Why didn't you take a cab?
Ross:- Between the traffic that time a day and all one-way streets, it'd take me twice as long. Besides, I teach the class three times a week. Who am I, Rockefeller?
Rach:- You won't be able to keep doing this.
Ross:- Well I have to, if I don't, they'll take the class away from me. And I put it in my family newsletter.
Rach:- You what?
Ross:- You've seen it, The Geller Yeller. Rach:- Right. Wow.
Ross:- I figured out a faster route, I'm sure I can make it this time. I just...I just can't be afraid to get a little bit hit by cars.
(after a while)
Ross:- (breathlessly in class) Yes, I made it! I'm on time! okay, why don't we all...(take a huge breath)...open our books to page23...(again a huge breath)... where...(again)...where you will see... a bunch of red spots. okay, why don't you all start to read while I...(Ross faints)
(after a while in class)
Ross:- So is every body here? I got here a little early, myself. Let us begin. (Ross wears roller skat shoes) Now, the hadrosaurids have been unearthed in two main locations. Here...and...here. Now, as for the hydrosaurs......(Ross almost goes to the classroom's door because of his poor roller skating skill. )If I went to American university, I would have to becaful to choose the class, looking where the building is.