Vania600 (バーニア６００) loves drawing trains, train stations, train activities, trains in fields, trains with girls, girls drawing trains and girls drawing on trains. I assume he also draws all these things while on a train himself.
I do not know why he enjoys the art of trains so much, but he does, and he is excessively good at what he does. As one of the top Pixiv artists, much of his work can be found in almost any of the various Pixiv art books.
For Vania600’s Pixiv: http://www.pixiv.net/mypage.php
For their site: http://sakuradima.harisen.jp/