 It has been suggested that making Transmission Gully a toll road would help resolve this problem and tolls would only cover a fraction of the funds necessary to build the highway.In May 2012, Julie Anne Genter, the Greens' spokeswoman on transport, described the motorway as incurring costs of $1 billion when the official business case benefits were $600 million, in order to ease congestion for an unlikely projected growth of 1500 vehicles.In February 2020 it was announced that the expected cost of $850m had been increased by another $191m.