Big Plans With Growing Price Tags

That point has been raised by opponents of the connector, who contend that an inner suburban rail line would generate at least as much economic activity as the highway.

Escalating costs are nothing new in the Washington region, or across the country. The price of the Springfield interchange, for instance, has more than tripled, from $220 million to nearly $700 million.

The granddaddy of rising prices is the Big Dig, the depression of Boston's Central Artery that was originally estimated at $2.6 billion but has turned out to cost $14.6 billion.

Lewis also cited Dulles International Airport as an example of a project for which benefits did not justify costs -- at least for its first 25 years.

"Everyone says: 'We built it way ahead of the curve. Aren't we smart?' " he said. "In fact, if we had the money over 25 years, we could have had infrastructure projects with much bigger benefits relative to their costs than Dulles Airport."

Transportation experts said faulty figures are almost inherent to big projects, because initial estimates are calculated before detailed work is done.

Sam Carnaggio, manager of the Dulles rail project, said initial estimates are at best ballpark guesses. But he said when politicians use them to sell projects, "it becomes cast in concrete."

David Luberoff, a Harvard University researcher and co-author of "Megaprojects," said politics plays a significant role. "If you think about this as a political issue, you would expect that the advocates for a project will underestimate the cost and overestimate the benefits," he said. "That's clearly one factor."

On the Dulles rail project, "the budget estimated at $1.5 billion was based on drawings," Carnaggio said. "Those certainly aren't engineering drawings. There's no detail whatsoever. The costs obviously are going to be different as you get into the details."

Carnaggio said those details include bigger stations, $100 million for two power substations and inflating costs for the project's builder.

The financing plan for the rail project calls for the federal government to pay about half its cost, with toll collections on the Dulles Toll Road and other state money to cover a quarter and business taxes the rest.

A federal government assessment of the project last year rated its cost-effectiveness at "medium-low." That was based on its $1.5 billion cost vs. savings of an estimated 17,800 commuting hours each weekday. Carnaggio said costs have to come down to maintain that rating.