This 90-foot bridge in
Wales Scotland (whoops, the company is Welsh, not the bridge) is Europe's first to be made entirely out of recycled plastic, not to mention the longest plastic bridge ever built. More than 50 tons of plastic went into making the bridge, which can carry vehicles up to 44 metric tons (heavier than most tractor-trailers).
The bridge's beams are molded out of a thermoplastic composite made from post-consumer waste. It has a life expectancy of 50 years (with little maintenance since the plastic is so damage-resistant), and when it's worn out, you can just chuck it in the recycling bin all over again. Vertech, the company that made the bridge materials, calls it a "closed loop product" — fully recycled and fully recyclable.