The next phase of work on dualling the A9 Inverness to Perth road is due to get under way next month.
The announcement from Transport Scotland follows the awarding of two ground investigations contracts yesterday.
BAM Ritchies will undertake the contract totalling nearly £3million for the Crubenmore to Kincraig stretch.
Raeburn Drilling and Geotechnical Ltd will also undertake the contract totalling approximately £3.8 million for the Pitlochry to Glen Garry stretch.
Economy Secretary Keith Brown said: “The A9 dualling programme between Perth and Inverness is one of the largest and most challenging infrastructure projects in Scotland’s history and we will shortly be starting further vital ground investigations that will support the ongoing design work.
“These latest significant ground investigation contracts will help inform the design work for three of the sections to be dualled – Crubenmore to Kincraig, Pitlochry to Killiecrankie and Killiecrankie to Glen Garry – in total around 27 miles of the route.
“Over the next few months some of this work will take place on or near the live carriageway. In order to ensure the safety of both road workers and road users we will need to introduce traffic management arrangements.”