It depends. If there aren't too many people crossing, it's fine. I am traveling on a German passport, and it took me about 30 to cross. You get your emigration stamp, show your yellow fever vaccination, walk on, go to a both where they take your passport data down. On the other side, again, you show your yf vaccination, show your passport at one booth (he checks whether everything is okay with your emigration), then you walk to another, get your passport stamped for immigration, and, voila, finished.