Other considerations aside, the seat order gives a small incentive for the first player(s) to build a longer route (5+) for a bonus tile at the beginning of the game, while the last player(s) may be better off starting with a quick short route to upgrade his carriage faster. This is because, if the later player competes with the earlier player, he may end up taking a lower-valued tile, when they both finish the same-length route on the same turn.