The South Australian government has promised $1.115 billion to improve country roads and boost the regional economy in a bid to curb the state's road toll.
The money will be allocated in the state budget which will be handed down on June 18.
The state's largest mobility organisation RAA lobbied for urgent highway upgrades and an increase to rural road maintenance.
RAA road safety manager Charles Mountain said the funding will ensure these projects be delivered.
"With the closure of the rail grain service on Eyre Peninsula, the need to upgrade the roads that are going to be subject to increased grain movements is essential," Mr Mountain said.
He said he looked forward to the investment reducing road trauma and boosting the regional economy.
"The investment in overtaking lanes and shoulder sealing is welcomed because these measures significantly improve safety.
"By providing safe overtaking opportunities, it reduces the risk of run-off-road crashes due to crumbling road edges."
The highways to be upgraded will be the Lincoln and Tod highways on the Eyre Peninsula and Horrocks Hwy in the state's mid-north.
Premier Stephen Marshall described it as the state's biggest-ever investment in regional infrastructure.
The state's toll for the year so far is running much higher than the same time last year, with 54 fatalities compared to 35 in 2018.
