Underused railway lines could face the axe, Transport Secretary Alistair Darling indicated yesterday.
A "common sense" approach to timetables and services was vital, said Mr Darling, addressing a rail conference in London.
In the "vast majority of cases, rail will be the best transport option", Mr Darling said.
But he added: "If you have a service where, for example, only four passengers are using the service, then we need to ask questions about whether maintaining the existing rail service is the right way forward - or whether buses or light rail could provide a better and more flexible alternative for passengers."
Mr Darling told the conference that from April 4, in line with the Government's railways White Paper, rail infrastructure company Network Rail would be established as the single point of responsibility for industry performance.
NR takes over, in this respect, from the Strategic Rail Authority, which is being scrapped.
Mr Darling said it was up to NR to provide operational leadership and "lead initiatives to improve timetabling, day-to-day operations and the overall management of the network".
Mr Darling said that although train punctuality was improving, the picture was "still mixed".
He added: "Performance is what counts. Statements and announcements and initiatives are all very well - but what matters to passengers and customers is that their train shows up on time and gets them where they want to go, safely and reliably."
He said it was vital the industry did not "take its eye off the ball" when it came to raising standards and improving performance and reliability for passengers.
"There are still causes for concern," he said.
One future scheme that has been discussed is the possibility of a new, high-speed rail line between north and south.
Mr Darling said: "We need to look how demand might develop over the next ten to 20 years.
"That means looking at additional capacity, the possibility of high-speed service lines to the north and south. These are big issues that need to be looked at - and they will be." Mr Darling said there was every reason to be optimistic about the future of rail and that "great challenges" lay ahead.
"The right strategy is in place for us to deliver the improvements that passengers rightly expect and I have no doubt that the industry is committed to delivering a world-class service."
Speaking after his speech, Mr Darling said: "The rail industry is now mature and we have to ask grown- up questions.
"Nobody is talking about cutting back on the railway and my guess is that in the future most of the stations that are well used will be expanded."
He added that in some cases community rail partnerships could be the way forward for under-used stations and lines.
He went on: "I see a railway expanding and not a railway contracting."
On Tuesday, train companies and rail passengers expressed disappointment with the difficulties customers have faced trying to get cutprice tickets in advance of the Easter holidays.
The Office for Rail Regulation chairman Chris Bolt decided not to issue an enforcement notice on Network Rail over the Easter ticketing problem.
Meanwhile, Network Rail yesterday predicted that it would have delivered a 16 per cent cut in train delays by the end of the financial year and that passengers would see train performance at a fiveyear high.