The Joys Of Winter Driving
We've had heated football pitches for some years now, so why not heated roads?
Living in Yorkshire I am used to the cold, and have often driven through some pretty awful weather in Britain and Europe over the years, but this year hasn’t got off to a good start.
Waking up to a cold flat on Christmas Eve morning, it was to discover that my combi boiler had packed in, and although my local guy made it through a blizzard to get to me, it was only to confirm that I needed a new one, and the earliest he could do it was in five days time. Great.
So Christmas was spent wrapped in a duvet using next doors cat as a muffler, and wondering what my next electric bill was going to be as we (me and the distressed moggy) shared the fan heater which was on full blast. Even the chicken came in from the kitchen asking for the gas to be turned up in the oven, or could she have her feathers back!
As I live in Lower Wharfedale, it hasn’t been too bad, with about a foot of snow (so far), but with a biting north easterly to remind me why I don’t wish to live in Russia. Now many of you reading this will have had it far worse than I have, and may have been stuck in the snow and ice, or suffered power cuts and heaven knows what else. You have my sympathy, and trust you are OK.
As I watch my TV, (which is so old it is personally signed by John Logie Baird), my mind turned to the grit that is being spread on our roads, and discovered some facts that may be of interest to you.
For a start, it isn’t grit, it’s rock salt, and to stop it blowing away it can be mixed with molasses to aid it sticking to the road – or should that be ice. Even then it will be blown away in strong winds, and the mixture works best when traffic mixes it with the ice, but only up to about -6c, when it will freeze again.
So why, I asked myself, don’t we have heated roads? Even the railways have heated points to stop them freezing, so is it beyond our knowledge to have heated roads – motorways and ring roads at least?
So me being me, I sent off a request for information from the Highways Agency, who pointed me towards their website, and http://www.ha-research.gov.uk/projects/index.php?id=1238 , which whilst interesting, told me little I didn’t already know. So I bounced it back to them, and now received an enquiry number – progress of a sort – and was informed my enquiry had been passed on to the relevant department. I awaited the results....
In the mean time I Googled “Heated Roads”, and got 17,200,000 results, (!) so limiting it to the UK, I was directed towards http://www.guardian.co.uk/environment/2008/apr/25/solarpower.energy , which seems to be the most understandable link, and it would appear there are at least two options available, and there seems to be little doubt that we might be seeing the introduction of some style of scheme in the future, at least in accident hot spots - maybe. (This was written in 2008)
However, I have a question. How much of the gully do we heat? If the road is going to stay wet when snow falls, the water has to go into the gully, and then into the drains. Will the water in the drains still be flowing, or will that have frozen too? I don’t mean with a general frost, but what about the temperatures we are seeing today, anything up to -20c. I am sure that the boffins have already thought of this, for there is no use curing one problem and causing another, and I suppose we must await developments.
Anyway, the Highways Agency had passed my request around, and it ended up by me receiving the following;
The Highways Agency commissioned a trial of a heat transfer system on a two lane private access road near Toddington Motorway Services on the M1 between 2004 and 2007. This innovative technique has been used in car parks close to buildings that complete the heat exchange loop. Therefore, the trial was used to investigate the winter maintenance of the road surface and the heating of nearby building. Heat recovered during the summer was stored to heat the road pavement in winter. Such heating helped prevent ice forming on the road by warming the road slightly to keep it above zero degrees centigrade, when ice might otherwise have formed. Although effective for mild freezing it could not prevent ice forming during the most severe conditions, since the warming only raised the temperature by around 3°C compared with the adjoining unheated surface. So if the control surfacing was at -4°C or below, the heated section would also be below freezing.
The Toddington trial assessed the whole life costing of the recovery of heat for winter maintenance and concluded that such a system may be used to treat well-known cold spots on the highway network. However, such cold spots are usually remote and do not necessarily coincide with building infrastructure for the symbiotic relationship of the system. The system could potentially reduce the amount of dead-running a spreading vehicle would need to undertake, i.e. without spreading salt, to treat such a cold spot if other parts did not need treating. However, other research has indicated there are alternative more cost effective ways of achieving this.
Research by others on heated roads has indicated that the effectiveness of a heat transfer system is dependant on a number of factors including the depth of the pipes within the pavement structure, the type of fluid used in the pipes and the thermal properties of the materials within the pavement structure. At present heat transfer systems have been effective in car parks where the traffic is relatively light and the pipes can be installed near the surface, but have not been used in roads on the Highways Agency’s network. This is because motorways and major trunk roads are designed to carry heavier traffic loads, so have a more robust pavement design. As such the pipes would have to be deeper to protect them and the road surface from potential damage which in turn may compromise the effectiveness of the system. Further research is required to assess the suitability, effectiveness, durability and long term performance of such a system on a road designed to carry heavy traffic before implementation on the Highways Agency’s network.
In advance of this the benefits and associated costs would need to be properly understood to see if such research could be justified given there are many projects seeking to make the best use of the limited research funding. A separate research project to consider if we could reduce the amount of dead-running undertaken by our salting vehicles identified this type of heat transfer system as a possible solution. However, the conclusion was that this type of system would be difficult to justify compared with other alternatives and that the use of salt is very cost effective. Plus, given ice could still form on the heated surfaces, during severe cold, there would still be a need to have the winter service fleet available so there would be no costs savings associated with reducing the size of the fleet. For these reasons additional research is not being pursued at present.
So there we have it. It’s too expensive, which must have come as no surprise to you – although a big Thank you to the Highway Agency for giving such a full explanation.
One day, perhaps in our lifetimes, someone will come up with a solution to a problem which may be only occasional, but can still gridlock cities and our motorway network and put lives at risk.
It’s all well and good receiving advice not to go out unless it is a vital journey, but that is no good to the coaches already en route or returning from a winter tour or private hire, not to mention the lorries and car users just trying to make it home.
I have some sympathy with the Highway Agency as the buck will always stop with them, but a better solution has to be found sooner rather than later.
Oh by the way, a new boiler was fitted before the New Year, the cat returned to its owner, and all is well and warm again – thanks for asking!
