This is a add-on for the Highway construction set. Unzip it to your Highway Construction Kit Data folder, take the included icons named for each model, IE: hw000090.jpg and install them in the HighWay Construction Kit Index folder, and you are good to go.
I will be making other add-ons for that kit, including more of the dirt roads.
The bridge is wood plank. The roads are dirt, the sides are wood planks. This is the bridge half section.
The pieces are designed to overlap on the ends when they snap. The barriers are the wood planked sides, the rock areas can be seen, and add character.
You can download the set here: Click Here.