There is one called Bus Missions Mod but that doesn't seem to work anymore due to it not being updated in months. However, there are 2 'Build a Mission' bus mission mods that you could give a try if you're interested, City Bus Driver and City Bus Driver 2.
Go into your handling.meta file and look for fTractionLossMult and set it to zero and it should give you the same amount of traction you get when driving on asphalt.
.jpg)
