There is actually a button to do this. Connect the track to the bridge and make sure that the track gradually goes up it.
Your track should look likes its floating up to the bridge. Now press the advance bar in the track menu. More option now click the button that saws smooth splines (the right button that looks like a mountain with a candy cane on top) With that selected click the track and it makes a earth ramp. You can click more times for more effect.
This also works with splines, and you can always adjust your track and do it again if its not the look you want.
Hope this helps,
hert:wave: