As the Utah Transit Authority starts its first year of an aggressive 70-mile rail-expansion program, a lawmaker and a state official are questioning the value and feasibility of building a system that requires billions of dollars worth of subsidies.

In Salt Lake County, taxpayers will pay $1.2 billion over the next 30 years to build four new TRAX light-rail lines and extend UTA's FrontRunner commuter-rail system to the Utah County border. Residents in Utah County will pay $765 million to bring commuter rail to Provo, enhance bus lines and fix roads.

The critics' question is whether all this transit is worth the money. But mass-transit supporters say transportation issues aren't just about money.

In dense urban areas, it costs about the same to build one mile of freeway as it does to build a mile of light rail. Transit critics are quick to point out that roads carry more traffic. There's also the question of whether residents will really trade the freedom and convenience of their car to ride a bus or train.

"The vast majority of Utahns really like their cars and being able to go where they want, when they want," said Rep. John Dougall, R-American Fork. "My question is, how much are riders willing to pay (for public transportation) and to what extent should the public subsidize it?"

Last year, UTA received $138.5 million in sales-tax dollars from about 2 million people to operate its transit system. That amounts to $67.29 per person annually in the six Wasatch Front counties serviced by the transit agency. Residents pay the tax even if they don't use transit.

But UTA supporters say transportation issues include other concerns.

"The question is not, 'What costs less and what costs more?'" said Paul Bay, a UTA consultant. "The question is, 'What is the proper mix of local streets, arterials, freeways, buses and rail lines?'

What makes the most sense is to make the transportation system work. We need more balance."

In the November 2006 election, 69 percent of voters in Utah County voted in favor of raising the county's sales tax by a quarter-cent to primarily support commuter rail coming to Provo. In Salt Lake County, about 65 percent of voters supported a similar proposition.

About 54 percent of UTA's projected $638 million budget for 2007 is subsidized by local sales-tax dollars or federal grants. In comparison, only 15 percent of the Utah Department of Transportation's $1.3 billion budget for the 2007 fiscal year came from the federal government, while 85 percent came from state and local funding, such as the 24.5 cent gas tax and sales-tax dollars in Salt Lake County.