STAND ON THOSE LIBERTARIAN PRINCIPLES. Reason's Robert Poole is consistent about separation of powers.

A key to fixing the problem is to identify what should be federal and what should be state and local responsibilities. In principle, only the interstate highways - our key arteries for interstate commerce - should rise to the level of the federal government. Other highways, streets, sidewalks, bike paths, local transit lines, etc., are more properly state and local concerns.

Reserving the federal Highway Trust Fund just for highway improvements would mean a 25 percent boost in federal highway investment - about $11 billion per year, a good start toward repairing our aging infrastructure.

Good start is not the same thing as finishing the job. Repairs to the yellow and blue highways will involve local and state taxes. Perhaps, though, hard budget constraints for state and county highway commissions will concentrate the mind. And $800 million for 150 miles of faster passenger trains rather than an additional pair of lanes for 150 miles of interstate at upwards of $2 billion might be a bargain.

There's another source of revenue that Mr Poole overlooks.

The bottom line is that our interstate system is deteriorating, which could be devastating to our economy. Trucks haul 66 percent, by value, of all goods moved in America on these highways, and projections show that this volume will increase 2.5-fold by 2035. We can't continue to siphon money away from them.

He has to evaluate that percentage by value, because by ton-miles, it's advantage freight railroads -- the trucks move the goods over relatively short distances from large warehouses or intermodal yards. That's freight railroads that have come up with more productive methods of renewing the tracks, and capacity expansions that have not involved any federal money.

Passenger and freight railroading is sufficiently different that mixing the two types of traffic hampers the performance of both. The freight pays its own way. The freight railroads understandably object to handing over control of their capacity to Amtrak or to commuter rail authorities.

The trucks Mr Poole frets about are sources of congestion as well as hazards to automobile drivers. (The automobile drivers are also hazards to truckers.) But the trucks do not bear the full cost of the roads they congest and pound to pieces. So much for siphoning money. Privatize the highways, put the right tolls on the trucks. It's the libertarian thing to do.