The Highways Agency has launched a consultation on a proposal to reduce the speed limit to 60mph for a 32-mile stretch of the M1, in a bid to cut pollution.
The new lower limit would apply from 7am to 7pm, seven days a week from junction 28, near Matlock, Derbyshire, to junction 35a, north of Rotherham.
In a report on the BBC News website, the RAC says that, if implemented, this would be the first time that a variable speed limit had been used to reduce air pollution. The RAC also warns that reducing the maximum speed could "pave the way for similar restrictions on other sections of motorway" and there would "inevitably be a negative impact on business efficiency and individual mobility".
As well as reducing pollution, the Highways Agency says the move would deliver "reduced congestion, increased capacity and improved journey time reliability for users of the motorway".
The Highways Agency proposal comes as new EU guidelines on air quality come into force this year. The BBC News report says that Highways Agency believes that a lower limit is needed to ensure the new guidelines will be met on this section of the M1.
The Highways Agency consultation will run for a period of eight weeks until 3 March.