Note that I had to cram in some extra bits of wood to make this solution work. In the picture below, you can see a red node, this node is not connected to the white nodes on either side of it but only to the nodes above and below. (You can't have a section of wood less than one length long). The two nodes on either side are connected to each other.

This bridge actually doesn't break when used. The trucks (and cars) hit the steep ramp and slide backwards down to the bottom level. They then hit the star and continue on to the end.
If you don't know how to create a ramp of road material rather than normal wood beam elements, you need to start from one of the road ends and work your way to the location and angle that you need. After that you can delete the sections of road that you don't need anymore. You might need to zig-zag a bit to get the road parts to the location that you need.

This is a tough level. The trick is that the top section breaks off when the tanker truck is (almost) completely on it. It then swings across to gently (!) place the truck on the steep part of the ramp. There was a lot of trial and error to get this one to work.