The restrictions have cut congestion on the A14 in Northamptonshire
A day-time ban on overtaking for heavy vehicles on two stretches of the A14 in Northamptonshire has been made permanent after a successful trial.
The 18-month trial resulted in less congestion and improved journey reliability, the government said.
The restriction will be for lorries of 7.5 tonnes and over on a section of the eastbound A14 between M1 J19 at Catthorpe and A14 J1 at Cold Ashby.
Another restriction will be on stretch from J2 Kelmarsh to J1 at Cold Ashby.
Transport Secretary Andrew Adonis said: "We are committed to tackling congestion and making journeys on our roads more reliable.
"Before the trial, these two stretches of the A14 were often blocked by overtaking lorries going slowly up the hills. This caused frustration among car drivers and other motorists caught up in queues.
"The trial brought a welcome a cut in congestion and improvement in journey time reliability and we believe the people who use this road will continue to see the benefits now the overtaking restriction has been made permanent."