Railworks America

This morning something downloaded through Steam. Anyone know what it might have possibly been?

When you want to find out what has been updated:
Open Windows Explorer,
Browse to your Railworks folder, most likely under Steam/Steamapps/Common,
Click inside the little Search box in the upper right of the window,
Select 'Date modified' and pick a date from the calendar shown,
All folders and files changed that particular date should be shown.