On Colorado going toward the campus UCB, bus pulls to stop for pick up and I procide to go around. The bus pulls out with out a signal and cuts me off. I usually know that when the signal is on to not go around. I had to jump on the breaks as to not hit the tail end of the bus. The students and the rest of me working on the campus is hard enough at times with out the bus being a problem also.?! The RTD-Denver.Com was what was on the back with # 2117, this happened at 7:47 am, at Colorado near 28th street going west to the campus.