Green roads: Highways of the future?

Roads are part of the infrastructure that many of us take for granted, but they take us where we need to go, transport goods and keep countries together. They are an national and economical necessity. However, they are also a massive blow to the environment.

The planet's road system is a network that is growing at one of the fastest rates in history. According to the CIA World Fact Book, you are never more than three miles from a paved road in 97 percent of the continental United States. Not just that, but the total length of the world's roads is 15.99 million kilometres. In comparison, the moon is only 384,400 kilometres away.

Every nation in the world is constantly upgrading and expanding its road systems; China's latest Five Year Plan calls for the building and renovation of over 1.2 million kilometers in order to build "a road to every village." The likes of Brazil, Russia, India and Africa are not far behind, each with plans to massively invest in long-needed road infrastructures and America has seen President Obama's stimulus package give the country's highways a repair and maintenance budget.

However, whilst the economical benefits of roads are well known, not to mention the time saved from new routes, the environmental impact is often understated. Whilst disturbances to ecology's are often well documented and reported, it is the resources needed to actually make the roads that have the greatest impact on the environment.

For each mile of road constructed, tons of rock, concrete, asphalt and steel are needed, not to mention the fuel used to power construction equipment. A typical two-lane asphalt road with an aggregate base can require up to 25,000 tons of aggregate rock, showing why aggregates are the most mined resource in the world. More importantly, they're an non-renewable resource.

On top of that, the greenhouse gases emitted from the mining, transporting, heating, earthwork and paving work means that the construction of an average single lane-mile of freeway, produces enough pollution to equal up to 1,200 tons of CO2 - roughly the same amount as the total annual emissions of 210 passenger cars.

Now calculate that figure by 37,000 because that's how many miles of new road the United States laid down in 2007.

These figures, not to mention the other environmental impact of new roads, is the reason behind interest in a scheme dubbed 'green roads'. The EPA, Federal Highway Administration, Recycled Materials Resource Center and universities nationwide are all working on new concepts to make roads more 'green', be it recycling programs for products that include coal fly ash, slag cement and old asphalt or initiatives for storm water management.

As a result, various innovative and eco-friendly road products have begun to emerge. Thus far, the most promising are soil stabilizers and asphalt binders that provide the equivalent strength of aggregate base rock at a fraction of the cost and environmental impact.

Of course, whether these ideas are taken on board by agencies and firms used to doing things their way remains to be seen and change is no easy thing, but New York State Department of Transportation Commissioner Astrid C. Glynn believes it's possible.

Speaking to Reuters, he said, "By encouraging sustainable transportation project designs, we are taking significant steps to conserve our natural resources, enhancing the quality of our lives and reaffirming our commitment to future generations."

So could this be what will drive nations in the future? A road that reduces toxic and greenhouse gas emissions, protects watersheds, reduces landfill use as well as protecting ecosystems? It is a possibility, but only if nation's engineering, economic and construction firms get behind the wheel.

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