Sydney drivers are expected to fork out at least $123 billion over nearly four decades for the city's disjointed and mostly privately operated toll road network.
Modelling by NSW Treasury and transport officials show $64 billion alone will be paid under a deal struck by the previous coalition government with Transurban for the 33km WestConnex system.
"You can't even get a mobile phone contract without being told the minimum payment," Roads Minister John Graham said in a statement on Monday.
"And yet, NSW motorists have been signed up to more than $100 billion in toll costs without any disclosure under the former coalition government."
The toll bill, projected out to 2060, takes in figures for privatised concessions, including the entire WestConnex system, NorthConnex, the Eastern Distributor, M2 and M7.
It also includes figures for the government-owned Sydney Harbour Bridge and tunnel, and future M6 stage one.
Premier Chris Minns said toll road operations should never have been privatised.
"We are the most-tolled city on the face of the earth," he said.
Transurban, which owns the vast majority of Sydney's toll roads, says it is open to government input to make the system better including a review led by former ACCC chair, Professor Allan Fels.
The company said in a submission to the review it supports some of what has been proposed so far including distance-based tolling, geographic zones, access charges and time-of-day pricing to manage demand.
"Transurban is open and willing to discuss opportunities to improve Sydney's toll road network," the submission stated.
"At the same time, it is important for the Review to consider the benefits that drivers already experience each day."
The figure revealed on Monday is the overall bill that will potentially be paid by motorists and from which operators pay for their running costs, maintenance and other charges.
The figures were based on conservative assumptions, including a long-term inflation rate of 2.5 per cent and projected population growth, the government said.
The state recently hiked Sydney Harbour Bridge and tunnel tolls for the first time in more than a decade, introducing a 6.8 per cent increase to help pay for its $60 weekly toll cap for motorists.
Tolls on other motorways generally increase in line with inflation, although Transurban is guaranteed a minimum four per cent annual rise for some projects such as WestConnex.
Opposition transport spokeswoman Natalie Ward questioned the figures, dismissing the 40-year forecast as a "made-up number".
"If Labor disagrees with a user-pay approach, why are they still committed to tolling the M6 stage one and Western Harbour Tunnel, which are both government-owned projects they could remove the toll on tomorrow," she said.
NRMA spokesman Peter Khoury said Sydney's sprawling tolling system was disjointed and called for a standardised pricing structure.
"Tolls must be set at a fair price," he said.
"It's part of a broader discussion we need to have into more significant and meaningful reforms in how we tax drivers overall."
It comes as drivers wait to discover if NSW Labor's marquee election commitment to cap road tolls will apply to them.
About one in 10 drivers are expected to start sharing more than $560 million in toll refunds over two years when the $60 weekly toll cap takes effect in January.
The scheme was a key election pledge aimed at winning Labor seats in western Sydney, where the bulk of the city's tollways are based.
But Mr Graham last week declined to say how exactly the cap would be applied, including in the case of two family members sharing two tags on one toll account.
