BRITAIN:THE OLD question of how drivers of salt-spreading lorries get to work could soon be answered under British government plans to recycle summer sunshine collected by roads and use it to keep them ice-free in winter.
The UK's Highways Agency plans to install pipes underneath a section of road to gather solar energy in summer and recirculate it in winter.
Experts hope the scheme could be a way to treat the roads which are the first to freeze. Officials are also testing the technology to heat and cool buildings, cut energy bills and lower greenhouse gas emissions.
If successful, the pilot scheme could be extended to more roads.
An agency spokeswoman said a final decision on which trunk road to use for the trial would be made this year. The road should have maintenance work scheduled so delays are minimised, she added.
The scheme, known as interseasonal heat transfer, or IHT, will lay a network of plastic pipes filled with water just below the road surface.
In summer, when road temperatures can reach 40 degrees, the water is warmed and pumped to pipes insulated with polystyrene. In winter, when sensors detect the temperature at 2 degrees, warm water is pumped back under the road to heat the ground and prevent ice forming.
The plan follows a two-year trial on a little-used access road near the M1 motorway by scientists at the Transport Research Laboratory in Wokingham, Berkshire.
Scientists found enough heat was captured in the summer of 2006 to keep the road above freezing for almost all of the next winter. On average, the heated surface was 3 degrees warmer than the surrounding ground.
The test also showed that heat from the road could be used to warm and cool surrounding buildings.
British airports, which must use chemical sprays to prevent ice and snow, are also interested.
Henk Verweijmeren, head of Invisible Heating Systems, invented the idea after spending Scottish summers moving sheep lying on the roads at night because the asphalt was warmer than the surrounding ground.
"If you have a tennis court in your garden, then you can use the energy it collects to heat your swimming pool," he said.