It has already completed a feasibility study and is now asking companies to tender bids to host off-road trials.

It works by a process called Shaped Magnetic Field In Resonance.

However, the director of Cardiff Business School's Electric Vehicle Centre of Excellence remains sceptical.

South Korea has fitted a stretch of road with equipment to wirelessly charge special buses
Electric cables buried under the road are used to generate electromagnetic fields, which are picked up by a coil inside the device and converted into electricity.

The government agency has announced plans to test wireless power-transfer tech that it hopes to build under the country's motorways and major A roads.

"But it sounds very ambitious to me. Cost will be the biggest issue and I'm not totally convinced it's worth it.

It aims to run the experiments for about 18 months before deciding whether to commit itself to an on-road trial.

Underground charging kit could extend the distance electric cars travel in a single trip
Motorists will be able to recharge their cars as they drive if a scheme being proposed by Highways England comes to fruition.

Even if the plan ultimately comes to naught, Highways England is also committed to installing plug-in charging points every 20 miles (32.1 km) on its motorway network over the "longer-term".

Last year, Milton Keynes also began use of a more limited scheme, which involves buses being wirelessly recharged via plates installed into road. In this case, however, the vehicles have to stop for several minutes at a time to receive the power boost.

In 2013, the South Korean town of Gumi switched on a 12km (7.5 miles) route that allows buses with compatible equipment to be charged as they drive over it.

"It's still very early days. Where exactly the trials will be has yet to be determined.".

The cost of buying and installing the charging equipment may ultimately scupper the scheme.
"As this study shows, we continue to explore options on how to improve journeys and make low-emission vehicles accessible to businesses and families.".

"What has been committed to is that by 2016 or 2017 we will hold off-road trials - in other words not on a public road," Stuart Thompson, a spokesman for Highways England, told the BBC.

Highway England says full details will be publicised once a contractor has been appointed.

But one expert questioned whether such a scheme would be cost effective.

It's not clear there's even a need for this.".

"The potential to recharge low emission vehicles on the move offers exciting possibilities," commented Transport Minister Andrew Jones.

"It makes sense to try it out, and the technology does obviously work," commented Dr Paul Nieuwenhuis.

Charge-as-you-drive technologies have already been pioneered elsewhere.