Instead of a possible statewide tax hike for transportation, lawmakers decided Friday to craft a bill that would allow individual counties to levy a quarter-cent sales-tax increase for roads, transit and airports.

The measure is being prepared for a special legislative session that is expected this month. It could help cover the costs of projects like the new St. George airport, commuter rail and light rail in Salt Lake County and expansion of roads in Utah County.

To impose the tax, counties would need to get approval from voters.

Sen. Sheldon Killpack, R-Syracuse, said Friday that he is comfortable that the bill will address concerns about a statewide tax hike and also suggestions that the increase only be implemented in Salt Lake County to pay for transit expansion. On Thursday, lawmakers had talked about putting a statewide ballot issue before voters and then, if it passed, imposing the increase during the 2007 Legislature.

"It's kind of the damned if you do and damned if you don't theory," Killpack said. "If you just make it available for only Salt Lake County, others will cry foul that you're favoring Salt Lake County. If you leave it open for everyone, people will cry foul that you're leaving it open for everyone."

Killpack said he wanted to wait before making predictions about whether the bill will be on a special-session agenda. Gov. Jon Huntsman Jr.'s spokesman, Mike Mower, has said in earlier interviews that the governor anticipates calling a session on Sept. 19 to discuss tax reform and possibly transportation.

"I feel good," Killpack said, "but we'll see."

Alan Gardner, a county commissioner for Washington County, said Friday that making a statewide, local-option sales-tax increase available is a good alternative for cash-strapped counties. In Washington County, which U.S. Census data says is the nation's fifth-fastest growing county, commissioners receive limited funds from the state to do road improvements, said Gardner.

The sales-tax increase "would be very helpful to getting our new airport underway," he said.

Late last month, the Federal Aviation Administration gave approval to plans for a new airport in St. George. The airport is anticipated to cost about $200 million. The federal government is likely to pay for at least 80 percent of the cost, but the rest will need to be subsidized with local dollars.

Under the proposed transportation bill, counties could use the quarter-cent tax increase for "regionally significant" roads, airports and transit projects like light rail or commuter rail. Killpack said it was unclear as of Friday what the process would be for determining which projects would receive money.

If approved in a special session, it is likely that only Salt Lake County would be able to present the tax increase to voters. The county currently has a proposal on the ballot for a $895 million property-tax bond to expand TRAX.

The sales-tax increase, if authorized by lawmakers, would be placed on the ballot in lieu of the property-tax hike.