Melbourne public transport expert, Associate Professor Paul Mees, has died in hospital after a battle with cancer. He was 52.

Mr Mees headed the debate over transport in Victoria for two decades, was the president of the Public Transport Users Association (PTUA) for years and taught at RMIT and Melbourne University.

As a leading international transport academic, Mr Mees was well known for calling governments to account over their plans for road and rail projects.

He was strongly opposed to the construction of Melbourne's East West link road.

In one of his final recordings before his death, he urged the State Government to rethink the plan.

"We have to that even on the government's own analysis can't produce a proper positive return on investment," Mr Mees said.

"If $15 billion is invested in the East West Link or even $8 billion in the eastern half that they wish to build now, there will be no money left for any substantial transport projects for Melbourne for at least a generation."

Tony Morton, the president of the PTUA, says Mr Mees was an inspiration.

"We can safely say that Paul has energised an entire generation advocates and activists here in Melbourne and to an extent, Australia," he said.