Most people take advantage of roads without a second thought, but that’s not the case for everyone. In rural areas, roads are the lifelines to survival. Without good quality roads, residents can’t travel for work or pleasure, children can’t get to school, and emergency vehicles can’t get in and out to rescue citizens.
The trouble with rural roads is that budgets are often stretched thin. County road departments struggle to construct new roads or maintain old ones. The lack of quality infrastructure limits residents’ livelihood—and limited economic growth prevents road construction even more.
Let’s discuss:
Rural roads include local streets, collectors, arteries, and interstates that pass through rural areas. What is a rural area? That’s up for interpretation. In the U.S., federal agencies don’t have a standard definition. They do make suggestions, though.
The U.S. Department of Agriculture’s Economic Research Service defines rural areas as counties with less than 10,000 residents where under 25% of the workforce commutes to metro areas for work.1 The U.S. Census Bureau defines rural areas as open countryside or towns with less than 2,500 people.2
At Substrata, we use the Census Bureau definition because it’s based on population—not commuting. We also consider population density. The Census Bureau doesn’t officially say how big “open countryside or towns” can be, so it's possible to have a two-square-mile, rural town with 2,000 residents and a population density of 1,000 people per square mile. That's denser than many urban areas! So, we focus on rural areas with low population densities of 25 people or less per square mile.
A two-lane, undivided rural road costs $2 million to $3 million per mile on average. That sounds astronomical, but it’s about half of what urban areas pay.3
Road construction costs vary based on factors like location and geography. For example, road construction costs more in Hawaii than Nevada because materials are harder to get.4 And in the mountains, rural roads cost over $5 million per mile—far more than roads on flat land.5
Rural areas pay for road construction mostly through:
Of course, bridges are another ball of wax. They often require additional funding through special programs.
Anyone who looks at a rural county’s road department budget knows there’s rarely enough money to construct new roads. Why is that?
Generally, it’s because of population. All taxpayers contribute to government road construction funds. However, the government distributes most funds to places with the most taxpayers. Since rural areas have fewer taxpayers, they get less money.
Additionally, not all local taxes fund road construction. For instance, property taxes primarily support public schools.
Finally, many rural areas get few—if any—federal funds. The federal fuel tax funds the Federal-Aid Highway Program (FAHP). The FAHP pays for designated federal-aid highways, but those only account for about 25% of public roads. Rural counties can’t use FAHP money to construct their own non-federal-aid roads.6
So, local governments must often conjure up creative, low-cost solutions.
To achieve low-cost rural road construction, county road departments must consider both upfront construction and long-term maintenance costs.
You don’t want to build a dirt-cheap road that’ll fall apart in two years—if you do, the money you saved on construction will just go to maintenance costs. However, you don’t want to overspend on construction, either.
You want a reasonable price upfront, with few long-term maintenance expenses. To strike this balance:
Since it’d be nearly impossible to share exact prices for everyone in every rural area, let’s look at an example of cost-savings with one product that works in most places: Perma-Zyme.
Perma-Zyme is a unique, enzyme-based soil stabilizer that permanently bonds soil particles together. It lasts 10-15 years on an unpaved road and up to 30 years on a paved road, all with little to no maintenance.
Many rural areas in the U.S. and other countries have successfully used Perma-Zyme for low-cost road construction, helping them stay on budget and making residents more satisfied with the local infrastructure.
See how Perma-Zyme worked on an unpaved road in White Pine County, Nevada.
In rural areas, many roads are unpaved because constructing dirt or gravel roads is much cheaper than paving and because the amount of traffic doesn’t require asphalt.
Many residents accept unpaved roads but not the problems that go with them like dust, mud, ruts, wash-outs, and more. People hate a dirt road that trashes their vehicles or—worse—is unusable.
On unpaved roads, counties struggle most with maintenance. And the time to prevent costly maintenance issues is during construction.
Using traditional methods, most counties and townships apply a gravel base and grade it onto the native soil to create a stronger load-bearing surface. Theoretically, that should decrease issues like dust and rutting.
However, gravel eventually washes away, sinks down into the soil, or migrates to the road’s shoulder. Then, the road maintenance team needs to reapply more gravel to the road, which cuts into their budget and time.
Working Perma-Zyme into the native soil eliminates the need for a gravel base. (You can add a thin gravel topcoat for traction, but it usually isn’t necessary.) So you’ll have few to no aggregate costs during construction.
And since the treated soil forms a concrete-like surface that lasts 10-15 years, it can withstand water, heavy traffic, and snow without rutting or washboarding. It’ll also greatly reduce dust. So you won’t need to buy more gravel, and you’ll pay little or nothing for other maintenance costs.
Applying Perma-Zyme takes slightly more labor and time upfront than traditional rural road construction methods. However, most customers calculated that their investment paid for itself within 12 months because they didn’t need maintenance.
Here’s how Perma-Zyme compares to magnesium chloride soil stabilization:
Paved Road Construction with Perma-Zyme
Paved roads are a luxury that many rural areas can’t afford to build or maintain. It costs an average of $2.6 million per lane mile to build a simple, minor arterial road on flat terrain.7
Paved road maintenance isn’t much better. Over time, paved roads often become full of potholes, cracks, and sinkholes. Reconstructing one lane mile of road costs $915,000, and resurfacing costs nearly $330,000.8
So with paved roads, you’ll need to reduce both construction and maintenance costs!
The road base is usually the most expensive construction element because roadbuilders have to excavate the native soil, haul it to another location, and import new material. Typically the new material is Type II aggregate, which provides a nice, stable base for the asphalt; the asphalt provides a strong, load-bearing surface for the traffic.
Using Perma-Zyme to treat the road base for low-traffic, rural roads can reduce construction costs by up to 80%. Perma-Zyme turns native soil into a strong, concrete-like base, so there’s no need to export and import material.
The other advantage of using Perma-Zyme to stabilize the soil and treat the subbase is that it greatly improves strength. In fact, R-value strength tests show Perma-Zyme is even stronger than most Type II aggregates.
That makes the design requirements less stringent for low-traffic rural roads. With Perma-Zyme, you can treat the native soil to a depth of six inches. Then, you can forgo the asphalt layer and put a couple layers of chipseal over the treated native soil. The Perma-Zyme treated base provides plenty of strength, and the chipseal provides a nice, smooth load-bearing surface for light, rural traffic that satisfies residents.
Treating the road base with Perma-Zyme and only applying a few layers of chipseal on top decreases the cost of the road by up to 80%. Additionally, a Perma-Zyme paved road can last up to 30 years with minimal maintenance. The formerly distant thoughts of paved rural roads can become achievable and repeatable!
Just remember that paving over a Perma-Zyme treated sub-base only works for rural local roads that get relatively low traffic. We don’t recommend it for interstates or arterial roads that get higher traffic volumes.
See how Perma-Zyme worked on a paved road for Box Elder County, Utah.
Constructing a rural road costs an average of $2 to $3 million per mile, and rural areas are traditionally underfunded. That puts a burden on local governments to stretch taxpayer dollars to keep the citizens happy and the local economy performing.
One way to do that is through low-cost rural road construction. By reducing construction and maintenance costs, you can maximize every dollar of your budget and fund other areas.
There are many ways to lower road construction costs. Using Perma-Zyme is a highly effective method that reduces upfront construction costs by up to 80% for paved roads. It also reduces yearly maintenance costs for both paved and unpaved roads to virtually zero. With Perma-Zyme, the roads that were once riddled with ruts, cracks, and dust become high-performing,reliable lifelines to help the local people and economy flourish.
To learn more about Perma-Zyme, check out this one-minute overview:
