I use the bus here for most of my commute to work and bike home after they stop running.
The racks they have here are the fold down type and if there are no other bikes on board you are expected to know how to lower it and properly mount your bike to it. When you remove your bike you are expected to raise the rack back up.
I have found them to be simple and easy to operate and they hold the bike very securely. The drivers here are actually very friendly and helpful but around here they know everybody by name and vice versa.