Western Avenue to Proviso Yard

The former Milwaukee tracks turn west-northwest and cross the former C&NW tracks at grade at Western Avenue (MP 2.6)—the Milwaukee Road's Tower A2 on the north side of the line—following which the east leg of a wye with the line south to Global I turns away to the southwest while the four track main line continues west, lefthand running. The speed limits at Western Avenue are 30 mph for trains continuing ahead, and 10 mph for those diverging, rising to 50, 45, 40 on tracks 1 and 2 (the southernmost pair), and dropping to 30, 30, 10 on tracks 3 and 4 (the northernmost pair)., as far as Kedzie. The Metra California Avenue Yard (a 16-track coach yard) lies along the north side of the tracks between Western Avenue and Kedzie, past a bridge over a north-south street, MP 3, and a signal bridge, while the west leg of the wye with the tracks from Global 1 (and the connectors from the B&OCT, etc.) trail in on the south side, east of Kedzie, followed by a through girder bridge over a north-south street.

At the crossovers and signal bridge at Kedzie (MP 3.4), where there was once a Metra station (short platforms still exist), the speed limit is 50, 45, 40  for  trains passing straight through, and 10 mph for trains crossing over, with the 50, 45, 40 speed limit continuing thence, past four bridges over north-south streets to MP 5.5 on tracks 1 to 3, while that on track 4 is 20, 20, 10 to its end at MP 4.5 (Harding Avenue), where it trails into track 3, followed by locomotive shops and a three-four track yard on the north side. At Keeler (MP 4.8), a line connects to the 40th Street Yard, heading away to the northwest. There is a grade crossing, a bridge over a north-south street, a signal bridge, and three bridges over north-south streets. The Belt Railway of Chicago passes overhead on a through girder bridge. From MP 5.2 to MP 5.6, there is an extra track (Track B) on the south side, with speed limit 30 mph, extending past the crossovers and signal bridges (second one at MP 5.6) at Kenton Avenue (MP 5.5), which have various restricted speeds for diverging trains, after which the speed limits rise to 70, 45, 45, as far as Vale (see below, MP 10.0), passing a signal bridge at MP 6.4, and ten bridges over north-south streets to Oak Park. The CTA Green line comes more or less alongside to the south (very close from just west of Lucerne), past closed "Metra" stations at Austin and Ridgeland and a signal bridge at MP 8.0, to the Metra station at Oak Park (MP 8.5), which has a platform and a lower-level brick depot on the north side, and an island platform between the center and south tracks.

The line continues past a bridge over a north-south street, a signal bridge at Lathrop Avenue (MP 8.9), the CTA yard on the south side, two bridges over north-south streets, and a line trailing in on the south side at Forest Park, and passes beneath the CN (ex-Wisconsin Central) line that bridges overhead on a through girder bridge. There is a bridge over a north-south street, a street alongside to the south, a Metra station at River Forest (MP 9.7), with a center island platform and a north side platform with a stucco depot, a bridge over a north-south street, west of the station, a signal bridge, crossovers at Vale (MP 10.0), with signal posts at the west end, where track 3 ends (but is being extended to Elmhurst, during 2010, with consequent changes in between) and speeds are 40, 30, 30, rising to 50,50,40 to MP 10.4, a deck girder bridge over the Des Plaines River, full speeds of 70, 60, 60, a grade crossing, a Metra station (two side platforms) at Maywood (MP 10.5), where there are Intermediate Signals, a grade crossing, a rail-served industry on the south side, a street alongside to the south, a Metra station, with two side platforms and a brick shelter on the north side, at Melrose Park (MP 11.3), a grade crossing (19th Avenue) at the west end of the station, extra track on the north side, a signal bridge at the east end of the crossovers at JN (MP 11.8), where speeds are 50, 50, 40 for trains passing straight through, and 13, 10, 10 for diverging trains, a grade crossing, and a cantilever signal bridge at the west end of the crossovers.

West of JN (now 25th Avenue), the two passenger tracks run southernmost in the formation, while the freight tracks at the east end of Proviso Yard are on the north side of the formation. The Indiana Harbor Belt bridges overhead on a through girder bridge, with a south-to-west connector that intersects, beyond a major freight facility that houses UP trailers on the north side of the passenger tracks, with the passenger line at Provo Junction (MP 12.1) and continues across, with crossovers to the freight tracks, which then diverge to the northwest. (There is also a connector from the north side of Proviso Yard that forms a wye with the west side of the IHB line, north of the bridge. In June, 2012, there's a new track formation with bagged signals on the north side of the IHB formation into Proviso Yard.)  The passenger line passes another freight track heading northwest, a Metra station, with two side platforms and a brick shelter on the north side, at Bellwood (MP 12.7), a grade crossing, a road bridge overhead at the west end of the station (that also crosses the yard), extra track on the south side, Intermediate Signals at Wolf Road (MP 14.2), a grade crossing, and a Metra station, with two side platforms, a pedestrian crossing, and a brick shelter on the north side, at Berkeley (MP 14.3),  before the passenger tracks and the freight tracks come back together, with an intermodal yard between them and dual highway bridges overhead, at the west end of the Proviso Yard facilities (including a freight bypass north around the northwest side of Chicago connecting all former C&NW lines) at the crossovers at HM (MP 15.2), the new end of Track 3, which have pole signals with multiple multi-lens heads at the east end, and a signal bridge at the west end. There are various speed restrictions for diverging trains on the section from JN to HM, but straight trains travel at full speeds.