Scotland's Transport Minister Keith Brown is due to announce the contractors selected to take forward three major road schemes in the South West of Scotland.
Over £36 million is being invested in upgrading two stretches of the A75, at Hardgrove and at Dunragit, and on a scheme to improve the A77.
There have been repeated calls for improvements on the road between Hardgrove and Kinmount section, following a series of accidents, including one which claimed a baby's life.
A local newspaper campaign gathered more than 4,000 signatures on a petition seeking an upgrade.
Mr Brown described the A75 as a lifeline for south-west Scotland, highlighting its importance as a main route to the ferry terminal at Cairnryan.