Image caption Major roads could be much gloomier at night if lights are dimmed to save money

Lights on thousands of miles of major roads in England could be dimmed during quiet periods in a bid to save money and reduce carbon emissions, it has emerged.

The Highways Agency is proposing to reduce light levels on A-roads when traffic levels are "very low".

Local transport minister Norman Baker said he supported the move provided safety was not compromised.

Research into when and where lights could be dimmed will begin in 2012/13.

"It is right that lighting authorities consider, in the interests of cost-saving and the environment, whether lighting can be sensibly dimmed or turned off, consistent with proper safety assessments Norman Baker, Local transport minister

The news emerged after Liberal Democrat minister Mr Baker provided a written answer to a parliamentary question from Conservative MP Daniel Kawczynski.

'Minimum lighting required'

Mr Kawczynski, the MP for Shrewsbury and Atcham, had asked Transport Secretary Justine Greening "what plans she has to revise guidance on the minimum amount of lighting required on A roads".

In reply, Mr Baker wrote: "The Highways Agency has plans to reduce the level of lighting on A roads when traffic levels are significantly below road capacity.

"The agency has no plans to reduce the level of lighting on A roads during the peak periods that occur during the hours of darkness or to temporarily switch A road lighting off when traffic flows are low.

"The level of light reduction will be based upon internationally agreed standards and made in consultation with the UK's Institution of Lighting Professionals."

'Cost-saving'

Mr Baker added: "It is right that lighting authorities consider, in the interests of cost-saving and the environment, whether lighting can be sensibly dimmed or turned off, consistent with proper safety assessments."

A Highways Agency spokesman said: "This is not about switching off lights on A-roads.

"However, we want to continue to reduce the carbon footprint associated with managing England's major A-roads and one of the ways we are considering doing this is dimming lights when traffic levels are very low.

"Any changes to light level will be determined in consultation with industry experts and will meet internationally agreed standards to ensure there will be no impact on safety for road users."