Drivers travelling between Skipton and Harrogate on the A59 are being warned to expect delays for the next six weeks.
Further work to the bank at the side of the road at Kex Gill is due to start on Monday with traffic lights and a temporary 40mph speed limit in place.
The work, which is aimed at stabilising the slope and preventing landslips, follows major work at the site completed in 2011.
Monitoring of the slope by North Yorkshire County Council revealed the need for additional drainage.
In 2011, the road was closed for five weeks while the bank was strengthened and the carriageway resurfaced.
But following heavy rainfall in the last two years, the council is having to do more work at the site to prevent possible landslides.
The cost of the latest project is £200,000.
Coun Gareth Dadd, North Yorkshire’s executive member for highways, said: “We apologise for any inconvenience that this may cause to road users; however, the works are necessary to enhance the stability of the slope at Kex Gill.”
Further details about the works can be found on the council website at northyorks.gov.uk.