Brian Tee said buses were the answer to neighbouring municipality Knox's public transport problems because they were "much cheaper and more flexible" than a rail line to Rowville.

A rail line to Rowville would pass through Monash suburbs, with train stations at Monash University and Mulgrave.

Mr Tee said buses were a better option because they could be changed and increased.

"It gives you a lot more flexibility around those areas compared to the cost of rail."

But he would "continue to keep an open mind".

"If we can get the maths to work, then that's different."

Mr Tee criticised comments by Knox Mayor Joe Cossari that the State Government had "neglected" Rowville residents on the rail issue.

"I think he's ignored the massive investment that's gone into public transport, with the huge increase in bus services.

"Not only the number of buses, but the times that they run, the routes that they run and the frequency that they run."

He said Cr Cossari had "ignored those great achievements, and it's a bit disappointing that he'd do that".

"I'm happy to have a discussion with him about the rail, but the Government is not going to do something unless the taxpayer gets value for money, and I'm not convinced that they will [for Rowville rail]."

The State Government is yet to deliver on a 1999 promise for a feasibility study into a rail line to Rowville.

Mr Tee, who is an Eastern Metropolitan MP, said proposed projects in Melbourne's east such as Rowville rail would need to be justified in order to proceed.

He assumed his new role following a cabinet reshuffle by Premier John Brumby last month. "My role is about working closer with local communities and councils to make sure we've got the transport that we need.

"It is about getting more and better transport options for people, so they are spending less time commuting and more time with their families."