C&M Subdivision

The Chicago and Milwaukee Subdivision (commonly referred to as the C&M Subdivision or C&M Sub) is a 85.5-mile (137.6 km) railway line running between Chicago, Illinois and Milwaukee, Wisconsin. It is operated by the Canadian Pacific Railway through its primary United States subsidiary, the Soo Line Railroad. This had previously been owned by the Chicago, Milwaukee, St. Paul and Pacific Railroad, commonly known as the Milwaukee Road.[1][2] It carries Amtrak's Empire Builder and Hiawatha Service, as well as commuter trains operated on part of Metra's Milwaukee District/North Line into Chicago. The Union Pacific Railroad operates their Milwaukee Subdivision, a former Chicago and North Western line, parallel to this route just to the east.

C&M Subdivision
Amtrak 90221, an NPCU, trails on a Hiawatha Service train nearing Union Station in December 2010
Overview
Status	Active
Owner	Canadian Pacific Railway
Locale	Wisconsin, Illinois
Termini	Milwaukee Chicago
Service
Type	Freight, passenger
Operator(s)	Canadian Pacific Railway, Amtrak, Metra
History
Completed	1873
Technical
Line length	85.5 mi (137.6 km)
Number of tracks	2–4
Track gauge	4 ft 8 1⁄2 in (1,435 mm) standard gauge
Route map 85.7 Milwaukee Intermodal Station west to Watertown Subdivision The Milwaukee Electric Railway and Light Company Menomonee River to Muskego Yard The Milwaukee Electric Railway and Light Company Kinnickinnic River Union Pacific Railroad Union Pacific Railroad Milwaukee Airport Railroad Station 77.9 Lake 72.0 Oakwood 69.4 Caledonia 61.8 Sturtevant wye, to Union Pacific Railroad 57.1 Somers 52.6 Truesdell Pleasant Prairie Wisconsin Illinois 46.5 Russell 42.9 Wadsworth Gurnee MD-N to Fox Lake Chicago North Shore and Milwaukee Railroad 32.3 Rondout (EJE/CN) 28.0 Lake Forest 24.2 Deerfield Lake Cook Road 21.1 Northbrook 20.5 Tower A20 south to Chicago Union Station

This line once carried the Milwaukee Road's fast Hiawatha passenger trains, including trains that regularly exceeded 100 miles per hour (160 km/h). For several years in the 1940s and early 1950s, trains were scheduled to run along this stretch in 75 minutes or less.[3] While stricter regulations eventually reduced the speed limit to 79 miles per hour (127 km/h) along this stretch, plans are in place as of 2010 to improve the line to support speeds up to 110 miles per hour (180 km/h)—modestly faster than historic trains that used the route.[4]