Undertake a Google search for news items referencing "potholes" and I can guarantee there will be items from a plethora of national and local news sources with stories about damage caused to vehicles; road safety issues; and the economic impact of poorly maintained roads.
For as long as I have been working in highways and transportation, which is over 20 years, I have seen the same report rehashed every year detailing the cost to repair the potholes and the economic impact on the UK; but the numbers have been getting bigger and bigger every year!
The latest reports suggest a cost of £16.3 billion to repair potholes in England and Wales; with an impact on the UK economy of £14.4 billion per year; to put this into context, the government recently committed £8.3 billion over the next 10 years to “fix the pothole problem”.
Anybody that drives, rides or cycles on our road network can’t help but notice the deterioration in the condition of the road surfaces; however, the potholes are a symptom of a wider problem with the approach to the maintenance of transport infrastructure.
Everybody, well most people, love to see a shiny new development with new roads and infrastructure opened up, usually with a big fanfare and local dignitaries cutting a ribbon and smiling for a press photo; but what happens when the highway gets adopted by the local authority and is added to a network which they are already struggling to inspect and maintain.
It shouldn’t be a surprise that the maintenance of highway infrastructure is one of the first things to be reduced in a time where local authority budgets are being squeezed; who is going to notice if the gullies aren’t cleaned twice a year, or the road markings aren’t refreshed, or if the condition and skid resistance of roads isn’t investigated? But in accepting these reductions in standards we must accept that the condition of the infrastructure will deteriorate and the cost for repairing it will continue to increase.
There are many reasons why a pothole may develop; material defects; overloading; failure of underlying materials; the age of the surfacing; but in most cases the ingress of water into the pavement construction is the key factor. The water can wash away loose materials in the foundation and in the winter the effect of the water freezing and thawing causes massive pressures which can tear apart the road. A road is designed and constructed in such a way as to minimise the amount of water that can infiltrate the construction, as soon as this is breached, through damage to the surface; badly reinstated service trenches; badly repaired potholes; there is a route for water damage.
Our highway corridors are not just used to transport cars and people on the surface; there are a myriad of services beneath the surface; drains, water, electricity cables, gas pipes, all with the requirement for repairs, and in the case of drainage and water, the ability to introduce water through leakage.
As highway designers we are always looking for innovative ways to improve our solutions, and whilst this is more difficult when improving, widening or repairing existing highways there are opportunities in new schemes to introduce preventative measures which will reduce the risk of damage to the road. On a recent new road scheme we were able to accommodate all of the new services within a widened verge footway and cycleway, minimising the risk of future need to dig in the road; we also designed a drainage scheme which met the requirements of SuDS legislation by providing a swale and limiting the number of drainage pipes in the ground. It is essential that more highway designers start to think more about the longevity of their solutions, and not simply about implementing what has ‘always been’ – it doesn’t work anymore. At Lynas Engineers I am incredibly proud of how our team think strategically about a solution, offering multiple outcomes that have long term, positive impact; and consider our rapidly changing environment and communities.
But good design and construction can only go so far; the road materials, particularly the surface layer, is subject to significant environmental and physical stresses, and over time this will lead to deterioration. It is critical that inspection and maintenance is a priority for highway authorities, and that sustainable and durable solutions are implemented; a short term approach of “fixing” potholes is neither of these and a long term programme of wider scale patching and resurfacing; as well as dealing with the underlying cause is required before we can start to reduce the cost of our aging infrastructure on the economy.
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