An Upcycled Bridge

The following was posted (the closest I can remember)

at the start of this bridge to help visitors guess what it was made from

 at the gift shop of the dinosuar quarry near Vernal:

I once traveled all over

from city to city 

but now I'm a bridge. 

What was I?

Lorenzo, Spencer, Ronan

A boxcar.
You could find the answer on the other side of the bridge.