Prior to 2020, the U.S. Highway 81 (US-81) intersection with Nebraska Highway 91 (N-91) near Humphrey in Platte County, Nebraska, experienced multiple serious and fatal crashes. This made the intersection the ideal location for the construction of the Nebraska Department of Transportation’s (NDOT) first reduced-conflict intersection (RCI). NDOT’s objective was to reduce the frequency and severity of crashes, enhance mobility for the traveling public, and improve reliability on Nebraska’s highway system. The RCI opened to traffic in November 2020.

NDOT’s broad goal was to implement additional RCIs across Nebraska, but it first needed to evaluate this intersection to determine if it was satisfying expectations.

In May 2021, NDOT contracted with us to perform an operational and safety performance evaluation of the intersection. We analyzed pre- and post-RCI implementation crash data and reached out to four peer departments of transportation to glean insights from their RCI experiences. We also worked with the Platte County Sheriff’s office to evaluate the number of crashes at the intersection post implementation. Additionally, we conducted an operational performance evaluation and independent review of the design and solicited public opinion on use of the RCI.

In the end, we suggested minor design modifications to future RCIs, but no significant issues were identified. The sheriff’s office reported no crashes in the 14 months between the RCI’s implementation and the study’s conclusion. This positive outcome underscores the viability of RCIs for NDOT, encouraging consideration for implementation in other statewide locations.