Transport Minister Gladys Berejiklian said the budget would include $91 million for the state's bus network.

While the lion's share of that will be spent on new routes and expanding existing ones in Sydney, the Illawarra wins two new bus routes of its own.

These are Route 52 from Flinders to Shell Cove and Route 41U from Dapto to the University of Wollongong.

Further details, including which companies will service these routes, is expected to be released in Tuesday's budget.