Between $10 billion and $13 billion is spent every year in Canada to maintain the integrity of roads, according to Carleton University's centre for advanced asphalt research and technology (CAART).

And every year the pavement corrupts, cracks, ruts and generally falls apart.

Experts admit that the value-for-money proposition is not as good as it should be.

There are two main causes. First is the overuse of roadbeds that were laid decades ago and were never meant to endure today's traffic volumes. Since 1988, there has been a 300-per-cent increase in trucks used for the just-in-time delivery that business demands, according to Transport Canada.

Ashley Fraser, Business Edge
Carleton University Prof. A.O. Abd El Halim has his Amir 1 asphalt multi-integrated roller ready to pave Canada''s roads.

The other cause is the weather in Canada, where the deep-freeze of winter can become the sweltering heat of summer - producing 50°C to 80°C swings that create fissures that expand and contract into frost heaves and potholes when water freezes and melts.

"(Both) these things are a real pavement killers and there's really no way to stop them without way more investment in materials and technology," says Steve Goodman, senior pavement engineer at the City of Ottawa and former program manager at the Canadian Strategic Highway Research Program (C-SHRP).

Prof. A.O. Abd El Halim of Carleton University, however, is convinced the main road-maintenance problem is with how they're laid and compacted, not with the quality of pavement.

Halim, who has studied pavement for 23 years and is the director of CAART, says his research shows it inevitably starts to fail within four years.

"They keep improving the material, but there are always more and more cracks because they are being put down with roller technology that is 120 years old," he says. "These roller drums have a point of compaction that is very small and uneven, just like rolling out dough, and this always leaves cracks right behind the roller.

"It's not a problem with weather because I've recorded it happening all over the world, the same in Egypt, where I come from, as in Canada or Australia. This is a systemic problem," he says.

Halim's solution was to create a compacter that exchanged the single steel-and-rubber drum with a flat surface machine called a hot-iron process asphalt compaction (HIPAC). The robot-like prototype is currently undergoing tests in Australia.

While roller technology may be old, there have been advances in paving technology.

During the past 20 years, paving technology has improved so dramatically that one Transportation Authority of Canada report claims a drop of between 25 and 33 per cent in traffic accidents because of improved road surfaces.

There still are, however, about 3,000 deaths and 18,000 injuries a year on Canadian roads, which cost the health-care system about $25 billion, according to government statistics.

In Ottawa, microsurfacing the areas leading into high-collision intersections with high-friction asphalt has reduced rear-end accidents by 60 per cent during the past three years, according to the city.

The city spends about $60 million annually on road maintenance.

Although both examples may have as much to do with driver awareness as with pavement quality, any improvement is welcome.

C-SHRP has just finished a 15-year study, piggy-backing on its U.S. SHRP sibling, that strives to improve Canada's highways.

R&D at pavement labs at Carleton, the University of Waterloo and the University of Calgary are developing technology, such as compacting machines and shear testers, to increase road integrity and maintain longevity.

There are two types of pavement: Asphalt, which is used in about 90 per cent of Canada's roads, and concrete.

Asphalt, or hot mix, is typically made up of about 95 per cent aggregate - anything from stone to recycled building material - and five per cent bitumen, an oil-based binder. Varying the constituents determines the pavement's flexibility, friction and noise co-efficients, and ability to slough water off its surface. Cost rises with the quality of the materials.

Today, industry R&D has arrived at its "platinum" brands: Perpetual pavement, a long-term, three-layer process, which under test conditions only needs resurfacing every 12 to 15 years; and stone-mastic asphalt, which uses larger, premium aggregate and about eight per cent binder to increase stability, permeability and longevity to 20 to 30 years.

Both emerged from R&D done by SHRP in the 1990s that revolutionized how asphalt was made and laid.

But both cost 2.5 times as much as traditional roads, or about $50,000 for a one-kilometre stretch of a two-lane highway depending on the location.

As a result, governments have been slow to make use of this technology, Goodman says.

Carleton's Halim has test results that show zero cracking and six times greater impermeability for various mixes of asphalt using HIPAC.

Its compaction strength of a relatively low six pounds per square inch (psi), compared to as high as 30 psi for standard machines, also produces 80 per cent less rutting, which can cause hydroplaning in wet and icy conditions.

Halim says HIPAC can reduce costs by 60 per cent during its life because it dramatically reduces the costs of labour, equipment and road replacement.

The test results are well known and Goodman says he's seen HIPAC's numbers and would love to have a fleet for Ottawa's roads.

"From what I understand it would create good savings over the life of the machine, but it's only in prototype so it's tough to say what it can do in real life. Right now we have to use what we have," he says.

There is no way for sure to know what the results will be until it has been used for several years, Goodman says.

Better machinery, however, uses less labour, creates shorter road disruptions and causes less wear and tear on vehicles, which Transport Canada estimates at about $200 a year for each of the 16 million passenger vehicles on the country's roads.

HIPAC's pricetag is about $100,000, but in a multibillion-dollar industry, small savings on a single process can produce huge savings overall because it costs five times more to lay new pavement than to rehabilitate old.

(Mike Levin can be reached at levin@businessedge.ca)