The Highways Agency has unveiled plans to switch off motorway lights permanently on a busy 15-mile stretch.
Active lighting will be retained at junctions and approaches to the stretch between Milton Keynes and Luton on the M1, according to the agency.
The plan forms part of the efforts to make the junction 10-13 part of the M1 a 'managed motorway', with variable speed limits and the option to use the hard shoulder in busy hours, managed by electronic overhead signs.
Switching off the motorway lights will not threaten safety driving on the stretch, according to the analysis made by the agency's experts.
Agency director Derek Turner said: "The money saved can be used for other measures on the strategic road network where it would have a more significant safety benefit and potentially save more lives.
"We anticipate achieving an annual reduction in carbon emissions on this M1 stretch of about 810 tonnes. Local communities will also benefit from reduced light pollution of the night sky."
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