More than €55 million has already been spent on BusConnects in Dublin.
The National Transport Authority says the expenditure includes the redesign of the networks, the design of core bus corridors and a future ticketing system.
The total budget for the BusConnects project is €2 billion.
Fianna Fáil TD, John Lahart obtained the figures and is calling for a more detailed breakdown of how the money is being spent.