Commuters have been warned that they will face four weeks of disruption on the A59 at Kex Gill as investigatory work is carried out.
Almost a dozen boreholes will be drilled as part of planned investigatory work to enhance the measuring and monitoring capability in the slope above the A59.
The work was announced by North Yorkshire County Council this morning (January 3) in a bid to help them anticipate any further movement in the hillside.
Work will now begin on Monday, January 23 but the county council stressed that the road will not need to be closed during this period.
Temporary traffic lights will, however operate 24 hours a day but Coun Don Mackenzie, executive member for Highways, said it was vital to prevent further problems.
He said: “Ultimately, we want to realign the A59 away from its current route at Kex Gill to avoid the risks of landslips, but this is a long-term project. In the meantime, we must do all we can to mitigate the problems that have closed the road in the past.
“We apologise for any inconvenience the work causes, but drivers will benefit as this investigatory work will help us to understand the landscape better, anticipate potential problems and minimise disruption to traffic.”
This stretch of road had also been affected by landslips in bad weather on previous occasions.
Commuters, as well as local residents and businesses, were blighted by an almost two-month closure of the road in January last year after substantial cracks were detected.
Heavy rain over Christmas shifted parts of the slope by up to 800mm, raising concerns over the amount of water that had become trapped as a result.
Contractors were forced to begin drainage and stablisation work on the road on January 18 before it was eventually reopened six weeks later.
Almost one year on, more work will be carried out to determine the geological nature of the ground and position of the water table.
Material collected from the boreholes will give a picture of the ground that will help determine what further work can be undertaken to stabilise the slope.
The county council said work on enhancing the monitoring facility for the slope could help identify further work needed to reduce the risk of the road being closed by further movement.
However, it also warned that any further works would represent only a medium-term solution to hold the slope in place while efforts continue to divert the route.