By Jennifer Whitlock
Field Editor

An I-40 bridge connecting Arkansas and Tennessee remains closed indefinitely after transportation officials found a fractured support beam in early May, leading to shipping delays and exposing tensions in the U.S. agricultural supply chain.

The Hernando De Soto “M” bridge, which crosses the Mississippi River, has been open to traffic since 1973. It carries about 60,000 vehicles each day, according to the Tennessee Department of Transportation.

Both the bridge and the river are major paths of food and agriculture-related traffic.

“The Mississippi River is hugely important to U.S. commodity supply chains related to exports,” Andrew McKenzie, a University of Arkansas agricultural economist, said. “When barge freight rates increase due to various demand and supply issues these higher costs are absorbed into price bids to farmers.”

In 2018, McKenzie coauthored a paper on barge freight contracts exploring the connection between barge forward contracting rates and grains transported along the Mississippi River.

When the issue with the bridge’s support structure was first discovered, the U.S. Coast Guard closed the river to barge traffic passing under the bridge. There were 62 vessels and 1,058 barges in line at the time. In an interview with Farm Progress, McKenzie said grains travel down the Mississippi River to New Orleans for export, and inputs like fertilizer travel inland along the same route.

If river traffic had remained shut down for a longer period, he said there could have been price impacts to markets north of the bridge closure falling because of excess supply. Markets south of the bridge could have experienced price increases due to lower supply.

But road traffic is still feeling the effects of the closure and likely will for some time.

The Arkansas Trucking Association estimated the bridge closure costs the trucking industry $2.4 million each day traffic is routed to other roadways.

“Using GPS data, we can discern that a previous 8-minute drive is now averaging 84 minutes. This additional transit time at $1.20 a minute for 26,500 trucks is costing the trucking industry more than $2.4 million each day that the bridge is closed,” Shannon Newton, president of the Arkansas Trucking Association, said. “Freight is like water. It will continue to flow. Our industry will continue to make deliveries. But if the additional expense is prolonged, it is likely to be passed on to consumers.”

Longer transit times and surcharges are expected to persist until repairs are made and normal bridge traffic can be resumed.

It’s a lesson in how interconnected our supply chain is to our infrastructure, according to Soy Transportation Coalition Executive Director Mike Steenhoek.

“People are often surprised by that, but it doesn’t take much for a problem in one part of our supply chain network to manifest itself to you individually,” he said. “You can have a problem over there, and suddenly, it’s your problem over here.”

He hopes the bridge closure brings renewed local, state and national attention to the problem of aging infrastructure and lead to investments to correct the issue.

“The ripple effect can be very pronounced. So, as much as we’re focusing on the impact of this major bridge, we can’t forget the rural roads and bridges a farmer has to cross to move his commodity from the field,” Steenhoek said. “That’s the link that makes all of the subsequent movements happen.”