The ban is one of several safety measures for the Woodgreen junction and others near it.
There have been two deaths at that location and one at a similar junction nearby since early last year, which is a shocking statistic.
Even if radical measures are agreed at that particular junction, there is a much wider problem with fatal accidents at such junctions. The junctions are known as ‘gap junctions’ in dual carriageways, at which vehicles turning right on or off the road have to travel over to a space in the central reservation, where they wait before completing their manoeuvre.
Motorists have to pass oncoming traffic and the back of long vehicles sometimes sticks into the one of the fast lanes on the main road while waiting to cross.
Such junctions emerged in the 1960s, as a cheap alternative to flyovers. They were appropriate to junctions and roads with low traffic levels. But newer roads, such as this part of the A26 in 2001 and the A1 at Loughbrickland in 2006, have been built with such junctions, that are wholly unsuited to roads with large intercity traffic volumes travelling at 70mph.
This is a particular hazard on the A1, where northbound traffic comes off the Republic sections of the Dublin to Belfast motorway and suddenly finds it is mingling with tractors and other vehicles criss-crossing via these junctions.
Long term, all such junctions on major routes must be closed and replaced. Local traffic might have to undergo the nuisance of driving perhaps a kilometre or so to the left to a flyover before being able to turn right. But the authorities will have to withstand complaints if they are to stop such deaths.
In the meantime, 70mph limits on parts of roads with gap junctions should drop to 60mph, enforced with speed cameras, but with the limit returning to 70mph when the junctions are replaced.