A new Structural bridge found Metadata / Game Objects / Environment in CAW. You need Ambitions or a later pack and to place the packages in both the mods/packages (Sims3 ) directory and in the "The Sims 3 Create a World Tool/ Packages" directory for the Structural bridge to show in your game. You have to make sure that you attach the road ends on both sides to the Structural bridge ( blue squares ).There is an earlier post explaining how to install items in CAW.
Importing packages into CAW
Structural bridge (MediaFire)
Concrete and wood bridge for CAW
Really damaged wooden bridge for CAW
Old Roman bridge for CAW
Structural bridge for CAW
Old bridge for CAW
Bridges - ultra modern suspension for CAW
Bridges for CAW - Suspension 1
PS I've used 2 Structural bridges as per above pictures. Place the 2 bridges next to each and the blue squares will automatically attach themselves in the middle. The 2 bridges have to be perfectly aligned and at the exact same height.