How to append the Asset into your scene
To use this Asset, just go into the destination project and click on "File" > "Append" , then navigate to the file you downloaded and append the Group (not the Object!) with the name "Asset_bridge_small".
How to adjust the road geometry
To adjust length and shape of the road select the curve below the bridge, go into edit mode and translate the individual points.
How to adjust the width of the bridge
In order to change the width of the bridge, just select and move the little cube next to the beginning. I is locked to one axis and can only be moved to a certain extent, so there is nothing to break!