It is second only to the BNSF Railway Line. The line is triple-tracked from Clybourn to just southeast of Barrington, with a bidirectional express track, and double tracked from Barrington to Harvard. The McHenry branch is single-tracked. Historically, double track was maintained from Harvard to Baraboo, Wisconsin. A now-gone portion of the Union Pacific / Northwest Line diverged at Harvard and passed through Beloit, Wisconsin, and reconnected to the main line at Evansville junction to allow a separate passenger and freight line. Around the time the Beloit line was abandoned, the railroad single-tracked the line from Harvard to Janesville. Since 2014 annual ridership has declined from 11.6 million to 10.6 million, an overall decline of 8.7%. The branch, which formerly had service north to Williams Bay, branches off from the main line north of .