An intricate maze of gravel roads surrounds Iowa’s towns and cities. Drive down a gravel road on a dry day and your car will kick up a cloud of dust. Travel on a wet day and you may find yourself in a muddy, slippery situation.

The state of Iowa has more than 115,000 miles of roads. Gravel roads make up about 58 percent of the state’s total road miles.

In this installment of Curious Iowa — a series from The Gazette that answers questions about the state, its people and our culture — we look into why Iowa has so many gravel roads. We’ll also respond to curious Iowan Patti Stutzman of Kalona, who wondered how much it costs to maintain gravel roads each year.

Why does Iowa have so many gravel roads?

The simple answer is that it’s expensive to grade, pave and maintain asphalt and concrete paved roads. So, less frequently traveled roads are typically gravel or dirt.

For some context, Iowa’s road system started from trails made by Indigenous people and territorial roads. These roads, including one that stretched from Dubuque through Iowa City to the Missouri State Line, were established before Iowa was admitted into the Union.

Congress allocated funds for military roads in the territory. The purpose, The WPA Guide to 1930s Iowa said, was “to expedite the movement of soldiers in case of Indian uprisings or frontier difficulties.”

As European immigrants expanded settlements westward, demand grew for roads between towns. According to “History of Iowa’s Secondary Roads” by Stan Ring, Iowa had more than 100,000 miles of dirt roads by 1900, although they “had been opened and graded by township trustees with little concern for inter-township or county wide movements.”

The 1900s and 1910s saw the establishment of the Iowa State Highway Commission, Iowa County Engineers, and a 6,400-mile primary road system and primary road fund.

“You built the roads from what dirt was available at the time,” said Brian Moore, executive director of the Iowa County Engineers Association Service Bureau. “And over time, you used the material you had available to upgrade them and because of the sheer number of miles, a lot of it was gravel.”

According to the Iowa DOT, the first concrete pavement was installed in 1917 and asphalt paving came in 1928. According to the WPA Guide, in 1937 there were almost 5,500 miles of paved highways and a total of 102,533 miles of Iowa roads.

How much does it cost to maintain gravel roads?

Across Iowa, you’ll find concrete or asphalt paved roads, hard surfaced chip seal roads, gravel and dirt roads.

Moore said gravel roads cover the most miles across the state, and they are the most cost effective to maintain.

Linn County Engineer Brad Ketels said that three factors go into consideration when determining a road’s surfacing: use, need and development.

“Gravel roads are upgraded to hard-surfaced roads based on traffic count,” Ketels said. “A general number for this upgrade to occur in Linn (County) is 400 vehicles per day.”

Ketels said in Linn County, 91 percent of traffic uses hard-surfaced roads, which make up 384 miles. Nine percent uses gravel roads, which make up 754 miles.

“Although the majority of traffic uses hard-surfaced roads in Linn County, maintenance of the rock roads is one of the top activities for our operations crews.” Ketels said.

In Washington County, there are 646 miles of gravel roads, 170 miles of paved roads and 86 miles of dirt roads. Washington County Engineer Jacob Thorius said that on average, gravel roads cost $5,000 to $6,600 per mile, per year to maintain. And it’s cheaper to maintain the gravel roads than to pave them, Thorius said.

In 2021, Washington County split costs 50/50 with Premier 1 Supplies, a sheep and livestock supply company, to pave three miles of road. Thorius said about 10 years ago, two other Washington County companies made similar arrangements. Thorius said the companies know the wear and tear their vehicles have on gravel roads. Plus, it’s enticing for employees to drive on paved roads.

Funding for road improvement projects in Linn County comes from a variety of sources, including the Road Use Tax Fund, Local Option Sales Tax and property tax levies.

In 2023, the Linn County Secondary Road Department reported that $11.5 million was spent on the following projects: 2.5 miles of asphalt paving, 4.7 miles of concrete paving, 83.7 miles of grading and rock overlay, four bridge replacements, 76.5 miles of pavement markings and two bridge deck overlays.

Widening that scope to the entire state, $263,383,268 was spent on roadway maintenance according to the Fiscal Year 2023 Iowa County Engineers’ Annual Report Summary.

Moore said there is not a goal to get all Iowa roads paved. Paving means regrading roads and adjusting them to handle higher speed traffic.

“There just isn’t enough money, so the counties do what they can,” Moore said. “They maintain what they can.”

And that means dealing with the unique challenges that arise from gravel roads, like muddy, soft roads during spring thaw.

“This year was nice because we didn’t have a lot of moisture, it wasn’t that cold,” Moore said. “But a lot of what happens to the gravel roads in the spring is caused by Mother Nature. Everybody’s trying their best to get everybody where they need to be.”

Thorius echoed Moore.

“The hard part is the road that everybody drives is the most important road to them,” Thorius said. “When we’re out taking care of roads, we’re looking at the system as a whole … we need to balance needs across the system.”

The other piece of the secondary road system puzzle is bridge maintenance.

“It’s a balancing act between where our resources are spent, and keeping everything in a manner where it’s as usable as it can be,” Thorius said.

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