The trunk road drops from 150m (492ft) to 20m (65ft) as it enters a valley at the braes in Caithness.
There have been accusations from business leaders and politicians that the problem with this section of the A9 was being "ignored".
The government said the project would progress "in the next few months".
Following a public local inquiry, ministers have given the green light for the improvements.
Transport Minister Humza Yousaf said: "We remain committed to delivering the much-needed improvements to the A9 at Berriedale Braes where the natural geography makes a challenging road alignment, particularly for HGVs and other long vehicles.
"Once the scheme is approved under the statutory procedures, a timetable for construction can be determined as soon as suitable funding becomes available."
Caithness, Sutherland and Ross SNP MSP Gail Ross said: "I am delighted that the Scottish government has addressed the issue with urgency. It is another important step on the way solving the issue of that particular part of the road.
"Vital time was lost during the public local inquiry and I now hope that there can be smooth sailing during the procurement process."
The Scottish government has said it is pushing ahead with planned improvements to a challenging hairpin bend on the A9 at Berriedale Braes.