If roadwork in Dakota County over the past 20 years was defined by laying pavement and adding lanes to keep up with growth, the focus for the next 20 years is keeping aging roads in shape and moving more people along them safely.

That means that in addition to roads, transit and trails figure prominently in Dakota County's 2030 Transportation Plan headed for approval later this year.

"None of these elements stand on their own," said Brian Sorenson, a county transportation engineer. "They all work together."

The idea is that a combination of cars, buses, bicycles and walking paths will better accommodate the county's changing population and travel patterns.

For example, senior citizens -- a group that's going to keep growing as baby boomers age -- may eventually prefer transit to driving their own cars on busy streets or longer trips.

And as officials have guided Cedar Avenue's evolution to a transit way, they are aiming to make the traditionally car-oriented corridor more pedestrian-friendly.

Already, because of the poor economy and higher gas prices, the total miles traveled on county highways has dropped about 4 percent annually since 2005.

"People aren't getting in their cars like they used to for every trip," Sorenson said.

Still, there will be plenty of road projects to be done.

By 2030, the county estimates that 109 miles of roadway will be at or approaching capacity.

And more than 200 miles of the county's total of 424 miles of roadway will be at least 60 years old. At that age, a new coat of pavement won't be enough to smooth out some roads. They will need to be rebuilt from the bottom up.

That can be costly, but when done right it brings a multitude of benefits, Sorenson said.

"We're managing the traffic, improving safety and replacing the road," he said.

What will get done will largely be a function of how much money is available to pay for it.

To do everything laid out in the plan through 2030, the county would need $1.25 billion. Planners estimate that slightly more than 50 percent of that, $658 million, will be available.

Yet there will be more planning for future development, whenever that may happen. Studies will examine possible corridors for an east-west thoroughfare along the less-developed southern section of the county and for a north-south thoroughfare somewhere between Interstate 35 and Hwy. 52.

"We don't have enough principal arterials to move larger volumes of traffic for longer trips," Sorenson said.

And in a sense, the current lull in development helps the county's road planning mature after a major growth spurt. To put it in perspective, consider this: In 1985, there were just seven intersections with stoplights on county roads. Today, there are more stoplights than that on Cedar Avenue alone, and other main roads, such as County Road 42 are often congested.

"There wasn't a whole lot of time. Development proposals were coming in one after another," Sorenson said of the past couple of decades. "We want to try to get in front of that."

Katie Humphrey • 952-882-9056