With so many potholes, why aren’t all of our roads made of concrete?
The state of the roads in the UK is often a source of much complaint and annoyance, with potholes appearing every winter and many long in need of repair or resurfacing. Yet there seems to be no one type of road surface. Have we simply not worked out which is best yet?
I have lived in the same fairly rural area most of my life, and while one main through-road has been resurfaced and repaired many times over the years, I am curious as to how the road surface in the housing area in which I live has remained in perfect condition, without potholes or deterioration, since the 1970s.
Road surfacing is dependent on council budgets and as always, there is no doubt that each council is trying to balance expenditure with longevity. So what are the choices?
Concrete road surfaces are long-lasting and this is indeed the surface that graces the streets where I live. It also has the benefit of being light in colour and so aids visibility after dark, especially in dry conditions. As far as I can see, apart from a few cracks, there have never been any potholes appearing in any of the concrete streets around where I live – concrete appears to be immune. So why isn’t this the universal preferred choice?
There are several factors that go into answering this. Concrete is overall more expensive to use as a road surface material and this may be the most crucial of these factors. It also has to be laid in thicker quantities than its alternative to prevent cracking, especially in areas where the subsoil is potentially unstable and may move depending on the amount of water it may contain.
In short, the preparation and time it takes to lay a concrete road surface might be inhibitive. My area of residence was a new estate when the concrete road surfaces were laid, therefore there was no traffic being diverted to other roads while the road laying took place; time was not of such importance.
An issue with concrete that might not immediately spring to mind is the gradient. Compared to asphalt, concrete will become problematic to use as a road surface if the gradient is too steep. This also leads on to another issue with concrete – its propensity to become a slippery surface during freezing conditions where it isn’t given the chance to thaw. On faster roads concrete is also (arguably) noisier, and on long stretches of faster road, low sun and wet conditions may make road markings harder to see. There is also an argument that road marking wear faster on concrete.
Yet it’s been shown that along with a pretty much maintenance-free lifespan, fuel consumption can be reduced on such surfaces when compared to asphalt roads. Rolling resistance might be especially noticeable when cycling and moving from one road surface to another.
When budgeting for a new road, then asphalt surely wins hands down – put simply, it’s much cheaper than concrete and quicker to lay with a faster drying time. Although oil price fluctuations and an overall trend for oil price rises can play a major part in determining the actual cost benefits over longevity. How many local councils actually take into consideration lifespan over cost is another matter entirely of course.
Asphalt is maybe not quite so self-levelling as concrete and requires a larger helping hand from the contractor. Perusing forums where such things are discussed as research for this piece I found many lamenting the dying art of being able to level roads properly – paving too. Again, if you are a cyclist, then I think you might be more sympathetic to this point of view than the driver of a vehicle.
The downside of asphalt is notorious – a shorter lifespan and non-immunity to weather fluctuations and tree root expansion resulting in potholes and the need for seemingly constant repairs. So does the cheaper cost really offer better value?
One aspect to be considered as an aside, is the delivery process of concrete versus asphalt. A concrete surface is traditionally ‘side-loaded’ onto the road surface, requiring access next to the road surface to be able to do this successfully. In the case of new-built areas such as where I now live, this is not an issue during construction.
Just how many councils actually take into consideration the long-term future of a new road is debatable. Arguably, like politicians and their promises, the quick fix and immediate satisfaction of the public outweighs the overall cost when calculated over a period of 20 years or so. It’s also worth noting that here in the UK, whoever is responsible for maintaining a road has a legal duty to do so. So if they do not and a pothole damages your car, then you might possibly be able to make a claim dependant on the circumstances. You might also consider taking out insurance against damage with a company like MotorEasy, who can provide cover for such things as alloy wheel damage as well as cosmetic insurance and tyre damage caused by potholes.
So after all these years, is the jury still out on what is the best road surface? Here in the UK, we still have 172 miles of trunk roads that are made from concrete. These roads consist of concrete sections to avoid cracking which are connected with expansion joints. Each section is also given ridges for added grip, which contributes to tyre noise. Around 1996 a new development given the nickname of ‘Whisper Concrete’ was introduced, yet it appeared that by now, the public had already had enough of such noisy road surfaces and were crying out for concrete roads to be replaced…
The Beast from the East
The Beast from the East in the winter of 2018 turned my local concrete roads into a skating rink, yet when the big thaw came, these roads shrugged the ice off without any issue. I wish I could say the same for the surrounding asphalt roads, many of which suffered and as the ice faded away were revealed to be in a dreadful pothole ridden state. Yet cost, perceived safety, and immediate results, means that the war is being won by asphalt – at least in the UK. In other parts of the world where funds for ongoing repairs may be less, a maintenance-free road surface like concrete is still preferred.
Exposed Aggregate Concrete Surface (EACS) technology has improved massively over the decades and new technology is still being tested, but the constraints in time and accessibility to lay – along with public perception – means that we are possibly less and less likely to see concrete as the chosen medium for new roads in the future. Maybe we just get what we wish for.
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