1) More passenger interaction/conversations.
2) Map DLC add ons (even longer routes and more choice/variety). I would definitely buy more maps to make the current one larger.
3) New random events
(Rare: Engine malfunctions, flat tires and ill passengers.
Uncommon: Traffic jams (could include sliders for this so people can pick how long in real minutes they want these to last), troublesome, travel sick or drunk passengers and having to pull over to the side to let emergency services get by you. Fallen trees after storms.)
4) AI has different types (Those who drive slow and carefully, those who are your regular good drivers and those who make mistakes and break small rules) so basically more realistic and unpredictable but not to the point where you can't get a drive done on time at all. Perhaps include a few sliders on what kind of AI people want in the game so you can get a mix of them or choose only two or one over others.
5) Ability to work for a bus company (drive routes made by other players). Perhaps in a contract type of feature. If this is not possible then drive routes that are randomly made by an AI company so that it doesn't get boring. Could even be a DLC if it had enough content to improve gameplay.
6) Ability for buses to become damaged (not visually) or dirty (visually). If damaged too badly it won't drive, if it's too dirty passengers complain and you should head to a bus wash at a bus depo whenever you can.
7) In the future perhaps you could have short routes and introduce your normal buses. Then for the longer routes you have your good old coaches. That way if someone does not have lots of time they can have a short drive, picking up passengers more frequently but if they fancy being a coach driver that is there too. It just adds more replay-ability to the game and stops it from getting boring as you can pick different roles.
Physics for coaches/buses so it doesn't feel the same driving on different types of roads.
Thank you for allowing us to have our say and hopefully we'll see some of our suggestions in the game 
