If the roads and shopping malls feel crowded now, consider this: Utah County is the sixth fastest growing area in the nation.

The U.S. Census Bureau has ranked the Provo-Orem metro area -- all of Utah County and Juab County -- in the top 10 fastest growers, by percentage, at 25.9 percent. The estimates measured change from April 1, 2000 to July 1, 2006.

Planners and city officials say that these kinds of growth rates have a dramatic affect on the counties and cities that experience the influx of new people.

The Census figures estimate that the area has a population of 474,180 -- a change of 97,402 people in just six years.

But the Governor's Office of Planning and Budget puts that number even higher. It uses a slightly different method to collect population statistics, and Shawn Eliot of the Mountainland Association of Governments said he believes the state numbers to be more accurate because it uses more specialized indicators, including building permit data.

The state-derived numbers also include less territory, as Juab County is not included in the estimate. They place the county's growth at 27.9 percent -- 103,531 new people in the last six years.

Eliot said that in the 1990s, Utah County saw growth of 40 percent. This, he says, is something that he fully expects to see again, noting that after six years the county has already matched the numerical growth of the 1990s.

Most of the impact from the growth, Eliot said, will be found on the roads and other infrastructure reaching maximum capacity. There will also be more homes, and the impact will be felt in social services.

Eliot says that the growth can be most easily seen when traveling on State Road 73 from Lehi to Eagle Mountain. "What used to be sleepy farm roads has become congested most of the day," he said. "It's going to get a lot worse before it gets better."

Provo City spokeswoman Raylene Ireland said that mounting transportation issues are a major reason for the "huge support for the quarter-cent sales tax increase," which was approved by voters last year. The increase will be used for putting in commuter rail.

"There's no question that transportation has become a more difficult and demanding issue," Ireland said.

Plans are already under way to alleviate the county's growing pains.

A number of roads are undergoing environmental studies -- the first step for road improvements. Eliot noted that the studies are only good for three years, so it is likely that these roads are going to get attention from road crews soon.

On the study list are State Road 92, Geneva Road, 1000 South in Lehi, Redwood Road, and the Interstate 15 interchange in Springville at 400 South.

Eliot said that these improvements are coming in preparation for I-15 to "go under the knife" in 2011. These roads are what are called "construction mitigation roads" -- streets that need to be widened and improved to keep people moving when the freeway's capacity is cut down.

"The good side of that," Eliot said, "is the Legislature and Congress over the past few years have been pumping a lot of money into the area ... $300 million last year."

Along with all those new roads comes new buildings. Last year, Eagle Mountain, Saratoga Springs and Lehi processed a combined 3,500 building permits. In the Traverse Ridge and IM Flash plant area, 1,700 building permits were issued.

Another mark of growth came from Elk Ridge, when its sewer system recently reached capacity and a moratorium on new sewer lines had to be put into effect.

Southern Utah, however, is growing even faster. St. George is ranked by the Census Bureau at number one with a growth rate of 39.8 percent.

Nathan Johnson can be reached at 344-2543 or njohnson@heraldextra.com

Facts about the Provo-Orem Metro Area

The largest population by age is the 20-24 year old population. The 20-24 year old population segment is larger than the total population of all residents 50 and older.

66.8 percent of housing units are owner-occupied.

Provo-Orem is the 6th fastest growing metro area in the US, growing 25.9 percent from April 1, 2000 to July 1, 2006.

The average household has 3.59 people.

94 percent of survey respondents identified themselves as white.

The median age is 23.3 years.

This story appeared in The Daily Herald on page A1.