For many, thoughts of spring include birds and flowers. For me, some other signs of spring include construction barrels, posted roads and, of course, potholes.

Drive down most of the roads in North Central Illinois and you will find at least one of those three things popping up this spring. This is a problem for the agriculture industry as roadways are important infrastructure for transporting agricultural products and other goods. Rough roads and construction zones can also be inconveniences to rural drivers and can cause costly damage to vehicles. It’s pretty obvious that Bureau County roads are bad, but why is that?

Last year, while at a college recruiting event with one of the soil science professors, he mentioned while Illinois soil may be good for growing corn, it is not so good for building roads. The state soil of Illinois is Drummer silty clay loam. According to the USDA, this soil type is the most common in Illinois. One of its main qualities is that it does not drain well. While this “black dirt” holds a water content that is great for growing corn and soybeans, that additional moisture causes the ground to expand and contract during the freezing/thawing cycles that occur throughout spring.

Most of the roads in this region of the state are made from asphalt, concrete or crushed stone with coatings of chip seal. According to the Illinois Department of Transportation (IDOT), these materials are specifically made using naturally occurring resources to the area. This not only reduces costs associated with transporting materials in, it also helps the roads better hold up to changes in temperature. In northern Illinois where the temperature change cycle is more extreme, a softer asphalt binder is also often used to reduce thermal cracking on asphalt made roads. However, cracking and potholes still occur because of the constant freezing and thawing that occurs in the spring to the soft soil underneath.

I think the best example of how Illinois soil structure does not support roads very well can be seen with posted country roads. Country roads are often constructed with crushed stone and layers of seal coating made from tar. As explained by IDOT, these roads are “posted” in the spring indicating that the weight loads that may travel across them are reduced. This type of construction can be easily damaged with just a few heavy trucks during the spring thaw when the soil under them cannot support the weight. According to Illinois law, however, these load limits can only be in place for 90 calendar days, as the roads can handle heavier weights most other times throughout the year and keeping them posted would be an unnecessary inconvenience.

You may also be asking how it is decided when to fix roads and where the money comes from to fix them. For example, I cannot recall a time when Route 92 through Walnut was resurfaced. However, within the last five years, Route 40 from Route 92 to Routes 6 and 34 was resurfaced and about two years ago, Route 26 from Route 92 to Princeton was resurfaced.

This is also shown on an IDOT road conditions map indicating that Route 26 is in excellent condition, Route 40 is green, but “preservation eligible” and Route 92 is red which is under “rehab/reconstruct.” Yet, according to another map on IDOT, all three of these roads are state-maintained class 2 truck routes, which suggests that they should be recognized by the state as having similar use and need similar maintenance. Hopefully Route 92 will be repaired soon, but I did not find anything to confirm that.

For road construction funding, prior to 2019, roads were exclusively funded by the motor fuel tax. In 2019 the Illinois General Assembly doubled the motor fuel tax, raised user transportation fees, such as the cost of vehicle registration, and shifted some general funds to the road fund.

Some people may think that Illinois has a lot of problems, but the roads here are definitely one of them. However, I know I will take a few potholes any day in exchange for the diverse agriculture that Bureau County and Illinois can produce thanks to the soil.

Kathleen Smith is a senior at Illinois State University where she is working toward an agriculture communications major. She is currently participating in an independent study project that requires her to write and submit news releases on agriculture topics. This is the second piece in a series she plans to submit to the Bureau County Republican.