Imagine you found the house of your dreams. The price is $450,000. You sign papers only to later learn the sellers made a mistake. The price for the house is actually $1 million. Fortunately, under California real estate law, you can back out of the deal. But if you were a California voter buying a train instead of a house, you might be out of luck.

In November 2008 California voters narrowly approved—by a vote of 52.7% to 47.3%— Proposition 1A. The measure authorizes nearly $20 billion in state spending to establish high-speed train service linking Southern California counties, the Sacramento/San Joaquin Valley and the San Francisco Bay Area.

At the time, the entire project was expected to cost about $45 billion. Proponents claimed funds from other public and private sources would cover the project’s remaining costs.

Tom McClintock, Jon Coupal and I co-authored the opposition ballot argument. We called the measure a “boondoggle” that “could cost $90 billion—the most expensive railroad in history.” We warned that no one really knew how much the project would ultimately cost.

After years of waste and mismanagement, California’s High Speed Rail Authority (CHSRA) has finally admitted what critics like us warned all along: “Building the entire system will take longer and cost more than previously estimated.”

In fact, the price tag for this risky transit gamble is now nearly $100 billion—more than twice the original estimate. The new number is greater than California’s entire annual state budget. To fund the entire project today, every Californian, including men, women and children, would need to write a check for more than $2500.

Without those checks, existing funding will only be enough to cover the first phase of the project connecting Fresno and Bakersfield. Should additional funding materialize, Merced and San Jose will be the next stops.

Despite the uncertainty, the folks at CHSRA claim California voters still want to buy this train. At a recent press conference, CHSRA chair and former Democrat Assemblyman Tom Umberg said, “There are some things that do change—development changes, cost changes. But the will of the California voter, I believe, remains the same today…”

Mr. Umberg might believe California voters are still on board, but I’m not so sure. Much has changed since 2008. California’s unemployment rate has risen from single to double digits, the state’s budget has become much, much tighter, and our credit rating has been downgraded to the worst of any state in the nation.

Further, the deadly collision of two high speed trains in China earlier this year has prompted new worries about the safety of high speed rail and led to the recall of 54 trains, reduced speed limits and a moratorium on new projects in that country.

Finally, renewed concerns about our nation’s debt and overall government spending make the outlook for federal funding far less certain. Congressman Kevin McCarthy has introduced a measure that would freeze federal funding and require a thorough audit of the project. The measure, introduced last month, is being co-sponsored by nine other California congressmen.

Perhaps California voters support high speed rail regardless of the cost. If so, high speed rail proponents shouldn’t fear a new vote on their new plan. If not, it would be a breach of contract—or as liberal columnist Tom Elias puts it—“a bait and switch”—to move forward with a costly plan that is little like the one Californians voted for three years ago.

As even Mr. Umberg admits, there are other options for improving California’s crumbling transportation infrastructure. One hundred billion dollars—or even a smaller portion of that number—could do much to improve the roads, freeways, ports and airports Californians use every day. The taxpayers who will foot the bill should make this call.

To that end, Senator Doug LaMalfa plans to introduce legislation putting the project back on the ballot. California taxpayers should support his effort and urge Governor Jerry Brown, the Legislature and the CHSRA board to do the same.

Elected in November 2010, George Runner represents more than nine million Californians as a member of the State Board of Equalization. For more information, visit www.boe.ca.gov/Runner.