The commuter line that defied state borders for a century

Science · Published 20 October 2026 Swipe more like this →

In short: While most regional transit systems are bound by state lines, the Union Pacific North Line has spent over 170 years crossing into Wisconsin. This unique arrangement was born not from a lack of planning, but from a pragmatic decision to use existing infrastructure rather than build new facilities.

The Union Pacific North Line (UP-N) serves as a unique corridor in the Chicago metropolitan area, stretching from downtown Chicago to Kenosha, Wisconsin. It is currently the only Metra line that travels outside of Illinois. This cross-border service is a legacy of the Chicago & North Western Railway, which was absorbed by Union Pacific in 1995. The route was originally constructed in 1854 by the Chicago & Milwaukee Railroad, with passenger service beginning in 1855 between Chicago and Waukegan.

The decision to maintain service into Kenosha, despite it being outside the Northern Illinois Transit Authority (NITA) service area, is rooted in economic efficiency. Metra opted to keep the service because it was already part of an existing agreement with the C&NW and incurred no extra costs. Furthermore, Metra determined that the Waukegan yard lacked the capacity to store the necessary train sets, making it more cost-effective to utilize the existing yard facilities in Kenosha rather than constructing a new yard within Illinois.

The line has undergone significant structural and operational evolution. For decades, Union Pacific operated the trains under a purchase-of-service agreement, but as of May 16, 2025, Metra began operating the service directly. The infrastructure has required massive investment, including a $166 million project between 2010 and 2022 to replace 11 bridges over 100 years old. By 2030, a $337 million initiative aims to swap out 11 more bridges spanning from Fullerton Avenue to Addison Street.

Despite the complexities of maintaining a multi-state corridor, the line remains a vital artery. In 2025, it became the third busiest Metra line with over 5.1 million riders. While ridership saw a sharp decline during the COVID-19 pandemic, the line has shown a notable 83% recovery rate of pre-pandemic weekday ridership as of October 2024.

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