What is the book called where two people write it and they each have their own character I think a page or something but at end characters are on train?

Here's why it fits your description:

* Two Authors, Two Characters: The book is written in alternating chapters, each focusing on a different character, August and Jane, respectively.

* Page-Turning Format: The chapters are relatively short, keeping the story moving and giving each character's perspective a distinct voice.

* Ending on a Train: The book concludes with the characters meeting on a train, marking a significant moment in their developing relationship.

Let me know if this is the book you were looking for!