Cardiff council fills nearly 9,000 potholes in 2009

Leaving a gap in the edge of the patch allows moisture in so it fails even more quickly in cold weather through the freeze thaw process I described earlier. Are these carried out poorly deliberately or through carelessness? The patch material will compress if it's not been compacted properly, again through laziness, lack of knowledge or deliberate poor work by the contractor.

If you've any questions about road construction, just ask. Next time you're in the Netherlands or Germany though, take a close look at the roads. Even in the big and busy cities you'll see that there are far fewer potholes. And no, those countries don't seem to spend more than the UK on road construction and maintenance overall. It's a question of doing the job right first time round.

another problem seems to be holes that are filled in then shrinking leaving a dip in the surface of the road, i suspect this is due to the hot stuff going in/on and then cooling down, surly thats not got much to do with budgets etc, but just the workforce not being arsed to put enough tarmac in the hole..?

Those hot sealed patches seem to be the preferred choice in Bath - they never last, partly cos I notice that although the job looks very neat the square patches often don't quite cover the entire hole leaving part of one seam in the repair exposed - I suppose it's in the contractor's interests to know there will be some holes to repair next year.

Patching the holes in a city like Bath is particularly daft cos so many of the roads are on steep hills and it has an exceptionally wet climate even by British standards, so they are never going to last more than a few months, but I suppose the repair budget is allocated annually and it looks smaller at budget review time than the cost of doing the job properly by resurfacing the road properly - which I'd imagine in somewhere like Bath means ensuring the substrate is properly stabilised too.

Oh, and repairing the potholes throws up another aspect of the daft way that local government wastes money even when it is supposedly 'saving' it. Round our way the refuse collections used to be taken from the back alleys behind the houses in a small van - it worked for a 100 years with no ill effects, but someone at the council decided it would be more cost efficient to use a dustcart and to have everyone cart their rubbish out to the front (never mind the inconvenience to the residents) the upshot is that the dustcarts being big heavy lorries (+ the new green waste dutcart) destroy the already fragile road surface in double quick time - the potholes on our road run in the line of the cart's tyre tracks. Blokey from the waste department doesn't care - so what if it adds £100,000 to the road repair budget, he's a hero for saving £50,000 on the waste collection budget…

Okay, I'll stop ranting now.

The patched holes failed because they weren't done properly and instead were done on the cheap. Getting a hot-cold seal to work in asphalt is a real trick and often it doesn't work. Get it wrong and moisture creeps in the gaps then when it gets cold you get the freeze thaw action and then the new repair just crumbles away. But UK councils prefer to do quick and cheap patch repairs in the forlorn hope that these will last and which anyone with any sense can tell them that they won't. If you use an infrared heater system you can heat up the edges of the patch so that the new asphalt joins with the old stuff but it costs a little more. Over the life of the repair, it'll save money but like I said before, our road authorities don't think that way and instead seem content to throw our tax money into repairs that fail regularly.

Freeze thaw action damaging joints is the biggest single cause of road surface failure in the UK and yet this is entirely avoidable.

Yes, I know what I'm talking about.

hey blackhound you know your tarmac dontcha!.

there's a few holes on my ride to work that were filled in probably no less than 3 weeks before xmas and since the cold 'spell' during that time they have come apart already, leaving what appears to be even bigger holes..

Of course if the roads were surfaced properly in the first place, most of the potholes wouldn't appear. In the UK we use a lot of antiquated road paving techniques and we also award contracts to the lowest bidder with the result that many/most roads are built cheaply using out of date techniques. It should be no surprise that these then have to be patched and repaired, eventually costing 2-3 times more over the life of a section of road than had the surface been laid properly using modern technology in the first place. This is compunded by a problem caused by the 'use it or lose it' approach to road repair budgets that results in surfacing work being carried out in winter. When paving roads in low temperatures, the asphalt cools down too quickly to be compacted properly so the road surface will begin to fail in just a couple of years in some instances instead of lasting 10-15 years. If you look at the way our European neighbours, the Netherlands and Germany in particular, construct roads you'll see that they spend a good deal less overall during the life of each km of road, while maintaining road surfaces with better overall quality. The Netherlands and Germany have similar ranges of weather conditions to the UK and also have many roads carrying similarly high traffic volumes as in the UK. On the rare occasions that European road construction techniques have been tried in the UK, such as with permeable asphalt, Britsh road engineers have gone against accepted European practice and changed specifications, resulting in early failures. Trials of permeable ashpahlt were deemed a failure in the UK and not suitable for UK conditions, despite evidence to the contrary from the Netherlands and Germany where roads have featured this type of surface since the early 1990s. The cause of the problem in the UK was the change in aggregate and bitumen specifications made by British engineers, not the technique itself.

There have been numerous reasons for this short-sighted approach to road construction and repairs. One of these is the rapid turn round of politicians through the Ministry of Transport and that those placed in the role have had little technical knowledge or understanding, a problem affecting the recent Labour Governments as well as the previous Conservative administration. I can think of only two roads ministers, one Conservative and one Labour, who had any understanding of the role. The latter was quickly moved on from the post because his common sense approach came at odds with party policy.

I could go on at length about this. It is my job after all. I'll spare you the details however. But believe me, the UK would save a huge amount on road repairs and maintenance if we'd follow the lead set by the Netherlands and Germany. It's a safety issue too and better planning would cut costs and reduce accidents but trying to explain a common sense whole-life costing approach to engineering to technically illiterate politicians (a disproportionately large number of our politcians are lawyers) concerned with re-election and who focus on short term policies has achieved little progress, no matter which party has been in power. We'd also have a good deal fewer potholes, fewer accidents and damaged vehicles/bicycles and less congestion resulting from roadworks.

Fewer than half that number in Blackburn, Lancashire!