Ground investigations for the two consecutive sections of the A9 dualling project are to start next week.
Fugro Geoservices will undertake the £3.6M contract for the Glen Garry to Dalwhinnie and Dalwhinnie to Crubenmore schemes totalling nearly 21km.
A Transport Scotland spokesperson said: “The first dualling scheme between Kincraig and Dalraddy has now been operating for some time and construction of the Luncarty to Pass of Birnam section is due to start soon.
“At the same time, design work on the A9 Dualling programme continues at pace with eight of the nine remaining dualling schemes being designed now at draft Order stage.
“The latest ground investigations starting next Tuesday for two schemes totalling 21km along with other GI continuing on other sections after the holiday break is tangible evidence of the work going on to deliver this ambitious programme.
“We apologise for any inconvenience these works will cause and would thank road users and local communities in advance for their patience during the works. The contractor will closely monitor the operation of the traffic management measures to ensure that delays are kept to a minimum.
“While we do not expect major disruption to traffic, we would ask drivers to plan their journeys in advance using the Traffic Scotland website, twitter feed or Traffic Scotland radio.”
Fugro was awarded the contracts last month and has previously undertaken ground investigations for the 16km stretch of the A9 between Crubenmore and Kincraig in October.