SALT LAKE CITY -- The amount of money the state receives from gasoline taxes to fund road construction shrank by more than $200,000 in the past year as rising prices had some motorists choosing to take public transportation instead of paying at the pump.

The revenue decrease is the third in the past 10 years and represents a less than 1 percent decline, according to the Utah Tax Commission.

"It's about as flat as it can get," said Charlie White, commission spokesman.

The state tax on gasoline is 24.5 cents a gallon and the drop in revenue, which is earmarked solely for construction, comes even as the state's population grows at a rapid pace. In 2005, Utah was the fifth-fastest growing state.

But it's unclear what effect the decline in revenue will have on scheduled construction projects. In February, when legislators were making budget projections, legislative staff forecast there would be a decline in motor fuel taxes and only slightly underestimated how much the decline would be.

"While it would have been nice to have more money, people are cutting back on driving and that could continue to be an issue on down the road," said Niles Easton, spokesman for the Utah Department of Transportation. "If that number gets bigger and bigger, that'll start to be a problem. If it's less than $500,000, we can still get done what we need to deliver to the public."

Easton said asphalt shortages and other increasing costs would likely have a greater impact on delaying construction than a drop in fuel tax revenues.

The tax commission figures show revenue from the motor fuel tax was increasing slightly, beginning last July. until winter hit. Between January and March, revenue decreased nearly 5 percent as the average price of a gallon of gas rose from about $2 a gallon to about $2.30.

In the same time period, the Utah Transit Authority's ridership swelled.

In January, ridership increased nearly 17 percent from the same time last year, to 3.3 million passengers.

"The correlation obviously between gas prices and ridership is definitely showing that trend nationwide that ridership increases because there are increase in gas prices," said Kyle Bennett, UTA spokesman.

The use of TRAX light rail is particularly popular with rising gas prices. In March, ridership on TRAX increased 43.9 percent from the year before to more than 1.4 million.

"You see people absolutely swarming the train," he said.

Others, however, say they can't change their driving habits even as the average price of a regular gallon reached $2.80 cents Thursday.

"I drive five days out of the week from Taylorsville," said Melissa Cardenas, a 27-year-old McDonald's employee in Salt Lake City. "I have to. It sucks. ... Right now it costs me almost $30 to fill up. They just need to stop raising the prices."

This story appeared in The Daily Herald on page D4.