"But Mr Roozendaal on Tuesday poured cold water on the suggestion, saying it was "not something the government will be part of".
"His whole theory is about taxing free roads into Sydney," the minister told reporters in Sydney.
"Sydney families already have high interest rates to deal with, high petrol prices. To face taxes on free roads into Sydney is an unacceptable burden for families in this city."
Prof Hensher's intervention follows the release of a report by the Institute last month, which called for car registration fees and petrol taxes to be scrapped and replaced with a congestion tax.
That plan was similarly rejected by Mr Roozendaal.
The introduction of a congestion tax is also opposed by the NSW opposition, which says public transport needs to be improved before such a change can be made.
"You cannot have a congestion tax without having proper public transport," opposition roads spokesman Duncan Gay told ABC radio on Tuesday."
Lesson: An 8% reduction of congestion is insufficient politically to warrant a whole new financing scheme.