Train Station Upgrade?

[sharkbait]

Hi guys.
I'm just curious. I see a bunch of threads in the "Train Station" part of the forum about upgrading the train station in the game. It requires 100 visitors, correct? Does Isabelle prompt you after having 100 guests? Or does she prompt you first, and then 100 people have to visit.
I'd love to get my visitor count up, but was just wondering if I needed a prompt first.
Thanks~

 

[PlasticPinkPiggy]

She will say you can change it after 100 visitors have been in your town (counting the same people who come multiple times)

 

[Aquadirt]

Porter the Train Station monkey will let you know that your town has an awful lot of attention and he's going to give some plans to Isabelle for renovation if you are interested in funding it.

 

[sharkbait]

Ah. Thank you guys!

 

[Scribbler397]

Porter tells you. I'm not even half way there unfortunately. MUST HAVE ZEN TRAIN STATION!