If traffic on I-15 in Utah County grinds to a halt, so will the economy.

That's the message local elected leaders and concerned citizens are trying to get out to the public before voters decide the fate of a sales tax increase to fund commuter rail and other transit and road projects.

A citizen-driven public awareness campaign is under way to ensure that voters know exactly what they'll be voting for or against when they cast their ballots on Nov. 7.

Meanwhile, local elected leaders are making the rounds in the business community, service clubs and other organizations to voice their support of the tax and the reasoning behind it.

Utah County voters will be casting ballots on whether to increase the sales tax by a quarter of a cent to address the county's transportation woes. If it passes, the tax would generate an estimated $765 million, based on what Mountainland Association of Governments officials say is a conservative annual growth rate of 5.5 percent.

Most of those funds would be allocated for construction and early operation and maintenance of a 22 1/2-mile commuter rail line from Provo north to the Salt Lake County border.

"Nobody likes a tax increase, but we need this one," said Thone Heppler, former regional president for Zions Bank and chairman of the public awareness campaign. "We need it to remove the congestion (on I-15) that's already here and will get worse. We need it to keep business commerce going so we're a healthy county with a healthy state economy."

The Utah County Commission unanimously voted in August to put the tax increase on the ballot. That decision had the support of MAG, which coordinates transportation planning in Utah County, as well as local mayors.

"We either pay for it now and put it in so we have the capacity for people to move in our state," Provo Mayor Lewis Billings said, "or we choose not to pay for it and then our economy eventually grinds to a slower mode as congestion increases and people can't get to and from their work."

Commissioner Steve White paints an equally bleak picture. I-15 in Utah County is due for a makeover in the next five to six years. Work will take about four years to complete, and during that time traffic likely will be limited to two lanes in each direction.

In addition, Utah County is growing by 18,000 to 22,000 people every year, increasing daily traffic on I-15 by 2,000 to 2,250 vehicles each year, White said

"We're going to have another 10,000 cars a day (on I-15) by the time we get four years down the road," he said.