Yes it is, but the automatic transmission should never let wheels slip when accelerating - unless the floor is slippery, in which case the transmission can't control that. Overall, the transmission would need a bit of work either. Gears sometimes change back and forth without any input change, gear which is in at ~50km/h isn't powerful enough to bring the bus to 60 (on a flat ground) etc.
This is the script from Morphi's mod, not altered in any way. I haven't experienced any problems with that, nor am I able to modify it, so for now it stays as it is.