"Passenger rail service, especially services at higher and high speeds, will require new safety rules, constant public capital investment and operating subsidies, and balance with freight rail service and the rest of the national transportation system -- and currently only some of these elements are in place, " according to a GAO report.

CNN: Is the U.S. turning a corner on high-speed rail?

Getting the right balance between road and rail will be a task that stretches the strategic transport authority.

ECONOMIST: Driving Britain off the roads

For a lighter option, the brewery's Iron Rail IPA has a nice balance of hops and fruit flavours.

BBC: Gateway to the Blue Ridge Mountains

But they go further: what is happening is not just an attempt to meet road costs, or even to balance the rival costs of road and rail, but an overt experiment in putting a money price on the environment.

ECONOMIST: Switzerland

The next important decision Mr Osborne must make is what balance to strike between current and capital spending, on roads and rail and the like.

ECONOMIST: Britain's emergency budget