The State Government has denied it has any plans to introduce toll roads in South Australia despite examining the impact of them on an upgraded South Road.
Documents released to Family First under Freedom of Information laws show the Government modelled the impact in 2010.
The Government again looked at the concept in June last year.
Infrastructure Minister Tom Koutsantonis says department officials often discuss various funding models when submitting proposals to Infrastructure Australia.
He says tolls are detested by motorists and do not work.