It really depends. Where I work, parking is awful and I have to walk 5 blocks from a parking garage to my building, because all the parking garages near my building are full and have a long waiting list (apparently the waiting list is 20 years long for the better parking). Meanwhile, the bus only takes 5 more minutes than driving, and it drops me half a block from my building. So in some cases, busses can be literally faster. To be fair, it also helps that I'm only half a block from a main road, and that busline happens to go directly to my workplace.