No income track or shares: Math is way too hard as it is, but thinking about math during gameplay is just wrong.
Instant cash on deliveries: You deliver a good, and you get cash. Right then.
No expenses: You deal with the reality of expenses every day when you're not playing games...why bring that nastiness to the game table? You never pay expenses for your locomotive (and there aren't shares/negative incomes either).
Most Money Wins: This part *is* just like real life.
No player elimination or bankruptcy: Both are not fun, so neither has a place in this game.
Players: 3-6
Optimal Number of Players: 5