Vancouver is on a quest to become the greenest city in the world by 2020. In pursuit of that goal the city has combined tricks old and new to help make their road repaving efforts more environmentally friendly. Vancouver's key contribution is recycling plastic into a wax that can be added to the pavement mix.
The key expenditure of energy in paving a road is actually the mixing, heating and transport of the pavement to the road. Normally, the mix must be manufactured and stored at near 320 degrees Fahrenheit. The new mixture, which is based on a European methodology, has been improved by the addition of recycled plastic from household products. This new mix can be made and transported at 250 degrees Farenheit. That saves gas to the tune of 20% at the plants that make the asphalt and in the trucks that transport it.
As far as the recycled plastic's contribution, it isn't huge. It makes up only 1% of the total mix, but that's 1% that isn't coming from anywhere else. Vancouver also hopes that the mix that includes it will prove longer lasting and easier to reuse. The mix is still in a trial phase, but has already been laid on three Vancouver roads.