The cost of tolls on some Sydney motorways are rising more than three times the annual rate of inflation with calls for the state government to reassess tolling arrangements for major new roads as motorists struggle to afford the charges.

Michael talks to Martin Locke, adjunct professor at the Institute of Transport & Logistics Studies at the University of Sydney, who says the pace at which tolls were set to increase over the next decade is unsustainable given that many people were already struggling to pay.