Plans to enforce 60mph speed limits on several stretches of new smart motorways to help reduce pollution have been rejected by the Government.
Transport Secretary Patrick McLoughlin has told the Highways Agency to find fresh ways to improve air quality in the three zones rather than lowering the speed limit.
The Highways Agency now has 18 months to come up with an alternative to its planned 7am to 7pm, seven day a week "go slow" on the new smart motorways being developed on the M1 in South Yorkshire and Derbyshire and the M3 in Surrey.
If the new proposals still include a temporary speed reduction, it'll have to be "absolutely necessary" to be given the green light by the Department for Transport (DfT). The Highways Agency has been told 70mph must be used when traffic is lighter such as at weekends or outside of commuting hours, too.
Mr McLoughlin said: "Let me be absolutely clear, I want all motorways to run at 70mph. While it sometimes makes sense to use variable limits to keep people moving, blanket reductions are not acceptable.
"Smart motorways are an effective and cost efficient way of increasing space on our roads, cutting jams and speeding up journey times and I am pleased to announce the start of work on these schemes."
The three new smart motorways - which will feature variable speed limits and the ability to convert the hard shoulder to a running lane at peak hours - are part of a £24 billion of investment in the road network by 2021.
These schemes will boost capacity by a third and improve journey times up to 10 per cent through the M1 schemes and 15 per cent on the M3, where average speeds are currently 45mph during rush-hour.
The M1 schemes (Junctions 28 to 31 in Derbyshire and Junctions 32 to 35a in South Yorkshire) commence operation from autumn 2015, and the M3 scheme (Junction 2 to 4a) opens to traffic in 2016.
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