Low Energy Roads

Ever rising fuel prices and the drive to lower carbon dioxide emissions is leading to cost reduction and environmental awareness walking hand-in-hand. One area this comes to the fore is in road-building and maintenance. And with the Government still being shy concerning investment in this area, lowering the energy used in roads is a bottom-line business strategy as much as a matter for corporate social responsibility (CSR).

Leading The Sustainability Drive

Jim Crick, chairman of the Asphalt Industry Alliance (AIA) calls on government to produce a coherent long-term strategy for road funding if the UK is to take advantage of the industry’s talent for innovation.

Sustainability is the word on everyone’s lips at the moment, and no doubt further discussion will be stimulated by new Government targets.

The sentiments behind them are extremely worthy and the asphalt industry is already keenly addressing the challenge of providing well designed, effective and safe roads while keeping a low carbon footprint.

But I have a concern and it is this. How can the industry continue to lead the drive for sustainability while draconian planning legislation and a lack of funding conspire against hard-won environmental benefits?

Well, there are a few solutions. Forward planning is obviously the best route to sustainability, allowing new road projects to be built to last, and to benefit from active planning of structural maintenance and use of durable materials.

However, this is not a situation in which we find ourselves very often. Local authority budgets allow for little more than pothole-patching – an approach that is not only a false economy but a major obstacle to sustainable, environmentally responsible road-building.

Designing failure

As an industry we have invested heavily in research and development to produce materials that are fit for purpose. Whatever challenges our clients face, whether it be increased skid resistance or durability, for instance, we can meet them.

These days that challenge is increasingly to find a compromise solution, so that clients can keep within their budgetary restraints. Our job then becomes to “design the failure”, or in other words, to design into the specification the minimum acceptable life of the road.

Using the right tool for the right job

If there isn’t enough money available we can at least make sure we use materials that are appropriate to the client’s particular priorities.

For example, one local authority that could not afford to replace failed road layers chose instead to build its roadway with binder-rich materials. This meant that while the surface layer would have reduced structural strength and therefore fail sooner through rutting, the lower levels would be protected from failure by being sealed from water ingress.

On the other hand, the complex for the London Olympics – becoming known as the “Sustainable Games” – will include some roads which are intentionally temporary. These will be high quality roads that are designed to carry traffic for months rather than years and their materials will be recycled when they are no longer needed.

In both these examples the industry has the flexibility and ingenuity to devise an appropriate strategy. Sustainability is a central consideration, although the drivers are strikingly different.

Investment in R&D

However, our industry is more than just reactive. We take the lead in constantly looking for ways to improve sustainability.

Serious R&D investment has resulted in cold mix and foam mix technologies that are able to create asphalt from almost entirely re-used material. Some of these products have been around for nearly 20years, yet their take-up has been quite disappointing. This is likely to improve, however, as oil prices rise and recycling becomes more financially viable (see Cutting emissions on the A45 and Tayside seeks Olympic Green articles in this section).

Recycling has long been integral to the asphalt industry. We already recycle old asphalt and planings, as well as using incinerator bottom ash, demolition waste and glass as aggregates.

It is important to consider the whole issue of recycling in its broader perspective as well. Achieving recycling targets for their own sake does not necessarily result in good quality, durable roads, which is how real sustainability should be defined.

What we really need is a long-term roads strategy that is properly funded. This will allow forward planning by both supplier and customer, equate to a better use of budgets, and provide a better return on investment in developments.

Our increased investment in recycling and improved energy efficiency comes at a time of major cost increases.

Over the past five years the hydrocarbon elements of asphalt materials – which are obviously linked to the crude oil price – have increased by a staggering 450%.

This has had a massive impact on our industry, and it has come at the same time as we are experiencing reduced sales volumes – the lowest, in fact, since 1981.
Alternative fuels are already being considered for the future, the most obvious of these being biofuels.

In the meantime, Government legislation prevents us from burning reclaimed oil, which negates our efforts to find sustainable and cost-effective fuels by increasing demand for virgin oil product and leaving us to find a viable means of disposing the previously reclaimed oil.

As with all industries, we have a responsibility to reduce our carbon footprint and, again, we are taking the initiative with industry-leading companies already having set their own voluntary targets for reduction of CO₂ emissions.

One particularly important aspect we are working on is standardising the method of measuring the carbon footprint of asphalt materials (read more on Colas’ Carbon Calculator on page 39). This will achieve consistency within the industry, ensure maximum efficiency, and give clients a clearly understandable means of measurement.

Unsustainable night work

For health and safety reasons, contracts are increasingly being undertaken at night. Unfortunately this is happening at the expense of sustainability, as planning constraints prevent asphalt from always being sourced from the most local, energy-efficient and cost-efficient plants. Instead, we end up moving materials far further than necessary and, as a result, increasing our carbon emissions.

The Department for Transport (DfT) has encouraged local authority engineers to go into asset management, and the biggest assets local authorities have are their roads. Managing, measuring and monitoring them properly is therefore a no-brainer.
Unfortunately, though, there seems to be a stumbling block to investing in this valuable asset.

Our industry is doing a great job, applying innovation and progressive thinking to a demanding situation.

We should be proud of our achievements in developing longer-life roads, more environmentally friendly products and production, reducing our carbon footprint and generally leading the sustainability drive.

We could improve even further with the help of joined-up Government thinking. This would help reduce the bureaucratic limitations and loosen the purse strings that make unsustainable practices – pothole-filling – all too common.

There is genuine goodwill on both sides: if we could just start pulling in the same direction, I feel sure we could make swift and significant progress.