Plans are underway for WA Transport Minister Dean Nalder to take an overseas research trip to investigate best practice in world transport.

The ABC has learnt that some of the destinations being considered include the US cities of Las Vegas, Portland and Baltimore, as well as Singapore and New Zealand.

Mr Nalder, who said Premier Colin Barnett had suggested the overseas trip, was initially unwilling to reveal the reason for the travel.

"We've been considering it ... I've been in discussion with the Premier about something we are working on but it's not something I can comment on at this point in time," he said.

"I'm hoping by next week we might be able to comment on it further."

The ABC has been told that senior public servants were canvassed to suggest places, people and agencies the Minister could visit while overseas to help develop his itinerary.

The trip is planned for the parliamentary winter break in July.

Asked about the destinations his department had flagged in correspondence with bureaucrats, Mr Nalder said they were "news to him".

He said nothing had been locked in - which meant he could also not give a cost for the trip.

"I wouldn't be visiting that many places," he said.

"I think we are just trying to find, on the issue we're working on, where are the best places.

"I think they would be considerations of places we could attend to."

Minister 'understands community concern on costs'

Mr Nalder said he could understand taxpayers being concerned about a minister planning an extensive overseas trip when the Government had recently considered axing late-night trains to cut costs.

"Look, it was a suggestion put forward by the Premier, the office is exploring it, we want to ensure it delivers an outcome that's great for the community," he said.

After a public outcry, Mr Nalder on Tuesday announced a Government backflip on the decision to cancel the late-night train services from next month, a move which would have saved the Public Transport Authority about $6 million over the next four years.

The Premier confirmed he suggested that Mr Nalder take the overseas trip, saying it was appropriate for senior ministers to undertake such travel.

"I did ask Dean Nalder to look at some of the international experience in transport," he said.

"We cannot sit in isolation in Western Australia and an important role of a senior minister is to see world's best practice in transport.

"Perth is a rapidly growing city.

"Big investments are being undertaken right now and we just need to see what's happening around the world.

"That is the job of a minister."

Mr Nalder's office later released a statement which said his office had asked the Department of Transport to recommend a list of places that were world leaders in transport systems.

"No trip has been booked yet, however I am considering a research trip in the parliamentary Winter break," he said.

"As I have said, no itinerary is set and nothing has been booked."

Opposition 'stunned' at 'reward' of trip

The Opposition's Ben Wyatt said given the Government had flagged public sector cuts in the upcoming budget, he was stunned the Minister was about to embark on a long, and taxpayer funded trip.

"What an extraordinary revelation, the Liberal Party is now utterly and completely out of touch with normal West Australians," he said.

"We saw Troy Buswell in the space of two years do identical European trips, and now we have Dean Nalder, fresh from his disgrace over closing late-night trains, heading over to Europe and Asia in the winter break.

"It seems that Liberal transport ministers' overseas trips has become something of a rite of passage.

"I am stunned that Dean Nalder, after multiple breaches of the ministerial code of conduct ... is now rewarded with a very expensive taxpayer funded overseas trip."