In addition to bidding for first position, players may also bid for positions 2, 3, etc. up to n - 1 where n is the number of players in the game. Any positions not bid for are maintained in the turn order from the previous turn. For example, players in positions 1, 2 and 3 were for some reason to bid for positions 2, 3 and 4, the previous position 4 player would go first on the next turn.
To display the turn order, each player may contribute a road and these roads may be placed in order in plain view.
Getting more buildings out onto the board more quickly makes for more of a planning game. Anyway it is unrealistic for bus line owners to be deciding the locations of buildings.
Thus, bidding for buildings is disallowed. Instead, before turn 1, randomly distribute buildings face down on all of the "A" spaces, turning them face up immediately after all have been placed. Before turn 2, do the same for the B spaces, before turn 3, the C spaces and before turn 4, the D spaces.