The extra funding was announced by Devon County Council alongside an additional £500,000 for highway drainage in 2017/18.
The local authority said it had continued to maintain 97% of A and B roads in good condition.
It said the additional investment would be used to improve road surfaces on lower category roads across the county.
The additional funding will be used for patching and longer term repairs to add life and resilience to roads.
Stuart Hughes, the local authority's cabinet member for highway management, said: "I welcome this additional funding for rural roads and highway drainage.
"It's good news for people living in rural communities and will go some way towards addressing some of the problems on our rural network."
Funding for drainage improvements will target areas where water is on the highway, which damages the surface, said councillor Hughes.
He added: "This will help protect our infrastructure by preventing water getting into the roads."
Devon's road network needs around £55m of capital investment every year to maintain its current condition.
But like many local authorities, the council faces an annual shortfall.
Around only £23m of the £38m allocation it received from the Department for Transport this financial year is available to spend on roads.
The funding also has to pay for maintenance of streetlighting, traffic signals, bridge repairs, drainage, safety barriers and public rights of way among other work.