MOTORISTS are advised of changed traffic conditions from next week on Waterfall Way to carry out safety improvement work on Dorrigo Mountain.

There will be intermittent lane closures with alternating flow arrangements from Monday 15 November while Transport for NSW installs slow vehicle turnout lanes at one uphill and three downhill sites on the mountain.

This will improve safety by providing motorists with more opportunities to pass slow vehicles.

Work will be carried out from 7am to 6pm on weekdays and from 8am to 1pm on Saturdays.

Work is expected to be completed by April 2022, weather permitting.

Traffic control and a reduced speed limit of 40km/h will be in place for the safety of workers and motorists.

The road will be open to two lanes of traffic outside of work hours but speed restrictions will remain in place.

Motorists are advised to drive to the conditions, and follow the directions of signs and traffic control.

Transport for NSW thanks motorists for their patience during this time.