I’m inclined to agree with the growth aspect – It could go faster.
As for your other two points… Building roads does not stimulate growth in any way, just lead it along a certain path. Passengers are very willing to take the train if you’ve got a bus or tram at both ends helping them onward. Again nothing is willing to travel for longer than twenty minutes. The more of the time they spend in a high speed vehicle, he further they are willing to go.