Minnesota’s economy depends on the efficient movement of freight. To improve safety, meet capacity needs, and plan for the industry’s future, transportation professionals are working to better understand challenges within the state’s multimodal logistics systems. As part of its 2025 focus, “Unpacking Freight: From Producers to Front Doors,” CTS held a recent webinar featuring results of two freight-related studies.
Roundabouts and commercial vehicles
Because rollover crashes at roundabouts involving heavy commercial vehicles (HCVs) have generated concern in the freight community, the Minnesota Department of Transportation (MnDOT) decided to study the issue. “Were the stories we were hearing anecdotal or was there data to support this argument?” said Mark Wagner, senior engineer at MnDOT’s Office of Traffic Engineering Safety and the study’s principal investigator.
An examination of five years of crash data (2018 to 2022) revealed that HCVs were involved in 164 property-damage crashes at roundabouts, compared to 182 crashes at signalized intersections. Additionally, the incidence of severe injuries or fatalities was 47 percent lower at the roundabouts. “The lower speed [at which] vehicles are entering the roundabouts is turning higher-injury crashes into lower-injury crashes. It’s a severity shift,” Wagner said. Most roundabout collisions are sideswipe crashes, which are typically low severity compared to the crashes seen at signalized intersections. “Angle [or T-bone] crashes at roundabouts theoretically don't happen,” he said.
However, the study did find a higher incidence of HCV rollovers at roundabouts: About 10 percent, or 15 of the 164 roundabout crashes, were rollovers; only one of the crashes at the signalized intersections was a rollover. The study analyzed factors including load volume and trailer use, traffic patterns, and crash data at approximately 200 intersections. One notable observation: About half of the rollovers occurred at just two roundabouts—one in Carver County and the other in the city of Worthington. “Those are some of the oldest roundabouts in the state,” Wagner said. He explained that MnDOT’s Geometric Design Standards Unit changed some of its design standards in 2018, adjusting the shape of the curb and other road features to reduce rollovers.
“Do roundabouts cause more HCV rollovers? In all fairness, yes. That was not just anecdotal,” Wagner said. “But as time has gone on, MnDOT and other agencies installing roundabouts have done a much better job addressing safety in design.”
The study also evaluated speed, inattention, driver age, road geometries, and work zones. “Sometimes by making investments in safety for one of these connected areas, we can support the bigger strategies,” Wagner said. “Overall, the study showed that roundabouts are a good safety strategy for commercial vehicles.”
Supporting commerce with cargo capacity
In the late 1990s, Mark Berndt, project director for multimodal freight transportation planning at SRF, worked for MnDOT on a study of air cargo capacity at Minneapolis–St. Paul International Airport (MSP). “There was concern that the availability of air cargo services at MSP might not be sufficient to meet the needs of Minnesota's MedTech and high-tech industries,” he said. “MSP is air cargo-constrained in terms of land use. There's not a lot of additional area to expand.” The study, concluded in 2001, was the first step in building a knowledge base needed to address the issue.
Today, some air freight is flown out of MSP in the belly of passenger planes. Airport improvements have supported integrated express freight (such as UPS, DHL, and FedEx) at MSP. However, every weekday 10 to 15 trucks drive to Chicago with cargo that is loaded onto planes at O’Hare International Airport. More capacity is needed closer to Minnesota’s commerce, Berndt said.
A newly formed group—the International Commerce and Mobility Forum—is exploring solutions. One is the Minnesota Freight Network Optimization tool, which uses freight demand and commodity flow data to shift cargo to more efficient and cost-effective modes. Additionally, a new green shipping corridor under consideration would move containers between Duluth and the United Kingdom across the Great Lakes.
Berndt noted that the group is also studying digital multimodal trade platforms. “A common trade portal would give real-time shipment information and allow for network and route optimization,” he said. “This whole frontier around digital platforms is something we're just on the cusp of and could create a real game-changer for Minnesota commerce.
—Amy Goetzman, contributing writer
