A lot depends on who made the coach and a few other things.. Speedometers used to go up to 120 on most all vehicles.. But a few went higher (And did too).
Many coaches, these days, are governed at like 80 mph, over 80 (or to be more accurate 8x where x can be any interger, zero included) the ECC cuts off fuel flow or otherwise "Throttles down" the engine (I have hit 82, full idle (Foot not touching pedal) down a slight grade, with a bit of tail wind (90-100 mph) and the driver info display said "Excessive Veh Speed" or something like that.. Had I had my foot on pedal the ECM (ECC ECM, same thing) would have throttled me bac.
So, if the rig's top speed is 80.. Why make the meter go to 120?
Home is where I park it!