The agency also said on Wednesday it had been given a guarantee for future funding with set limits for each financial year.
"National Treasury has now decided that Sanral's future issues will carry a state guarantee."
Sanral is a state-owned entity responsible for the design, financing, maintenance, operation and rehabilitation of South Africa's national road network.
R10bn borrowings
The agency's CEO Nazir Alli said it would be starting a new domestic medium-term note programme to raise funds through the issuing of bonds covered by a government guarantee.
In July last year, Sanral had approval for unguaranteed borrowings of R10bn but these borrowings reached their limit by this month.
"We wish to thank those who have participated during the past year and look forward to their participation in the future."
Alli said the agency would also be continuing with its monthly auctions on the first Wednesday of each month, starting in July.
Sanral also subjected itself to a due diligence exercise by independent ratings agency, Moody's.