"Hop In -Abby"

I was watching a train go by, and I saw "Hop In" graffiti'd on to the car, signed by Abigail (my current girlfriend in-game). Are you actually able to hop on the train or was it just a cool easter egg I found?

 

I've seen that too, pretty sure it's just an easter egg kinda thing.

 

It'd be really awesome if you could actually hop on and go on an adventure with Abby, kind of like one of her heart things. Maybe someone could make a mod for that.

 

That would be awesome

 

There's an erasure over it. Looking closely, I assume Sebastian wrote it along with the "Hi."
Take a look at Sebastian's Wiki page, it is stated he might admire her.

 

Sounds great.
Not matter what I'm doing, or where I am, I try to rush to see the train and the graffiti. Never mind what may fall from the wagons.
Maybe it is an efficiency thing in you're chosen path to race there and see the engine and of course, the graffiti.