A newly released analysis that showed the projected cost of high-speed rail has more than doubled - to $98.1 billion - has led some critics to suggest the idea should be scrapped. This would be a huge mistake for a state whose population is expected to grow by more than 10 million in the next two decades.

The California High Speed Rail Authority did exactly what it was asked to do: to make a clear-eyed assessment of the cost estimates, ridership projections and other assumptions behind this ambitious project. It also came up with a more systematic - and somewhat slower and scaled-back - plan for completing the link between San Francisco and Anaheim.

The upshot is that high-speed rail is going to be more expensive to build and more expensive to ride than voters were told in 2008 when they approved a $10 billion bond to get the project rolling.

"This is not a marketing plan, this is not a promotional plan - this is a business plan," said Dan Richard, a former BART director recently appointed to the authority by Gov. Jerry Brown in an attempt to bring fresh eyes and expertise to oversee the project.

"Sticker shock" was the phrase heard around the state Capitol when that business plan was released Tuesday. Senate Republican Leader Bob Dutton of Rancho Cucamonga (San Bernardino) called the project a "boondoggle that needs to be derailed."

No one was cheering the dose of reality. But this was a moment for Californians to take the long view. The stresses on our airports and highways are only going to intensify, as is the pressure to reduce carbon emissions. A $98.1 billion outlay for high-speed rail must be measured against the alternative. Creating equivalent capacity with 2,300 miles of highways, 115 new airport gates and four new runways would cost $170 billion - with a far greater impact on the environment, the business plan calculated.

None of the rail authority's numbers should be treated as gospel. They will be subjected to independent scrutiny in the months ahead. But as state Treasurer Bill Lockyer observed, for too long the authority's held a reverence for the "big dream" of high-speed rail but "showed little taste for confronting economic and political realities. That attitude has changed."

The size of the numbers and the magnitude of the challenge should not deter Californians from pursuing this dream. As Fresno Mayor Ashley Swearengin put it, Interstate 5 was once called too expensive and a "road to nowhere" when its construction began in the Central Valley.

The new business plan addresses one of the provincial concerns on the Peninsula: It proposes to blend the system with an electrified Caltrain, allowing the two train lines to share tracks and minimize cost and disruption. "It saves literally billions," said state Sen. Joe Simitian, D-Palo Alto, who had joined Rep. Anna Eshoo, D-Palo Alto, and Assemblyman Richard Gordon, D-Menlo Park, in pushing for a blended system.

More for you Opinion High-speed rail is on the right track

The planning for a high-speed rail system appears to be moving in the right direction with a business plan that is decidedly more pragmatic, realistic and transparent than anything Californians had been presented to date.