Street light use is being reduced in Leicestershire as part of plans to save money and cut carbon emissions.
From Friday, lamps will be turned off on sections of the A6, London Road in Oadby and Harborough Road, West Langton.
These 30 will be the first of 40,000 to be turned off and 2,000 dimmed to save £700,000 from its £3m power bills.
The county council said it was working closely with the emergency services to make sure the changes were safe.
The 2,000 lights on main roads will be dimmed between 2200 and 0700 BST.
The thousands of street lights to be switched off will be extinguished between midnight and 0530, starting with Quorn, Thurlaston, Dunton Bassett, Swannington, Smeeton Westerby, Lubenham and Croft.
Mike Preston, cabinet member for environment and climate action, said: "This shouldn't be noticeable and it will help to cut energy costs and reduce pollution.
"We do recognise there may be public concerns about switching off street lights late at night. However other councils, like Gloucestershire and Essex, have adopted this approach and found that it has not led to increased crime.
"Just by making these simple changes, we can cut annual carbon emissions by 3,000 tonnes - that's got to be worthwhile."