Clybourn to Mayfair

From the junction of the Harvard and Kenosha subdivisions, with I-90/94 alongside to the west and a bridge over West Cortland Avenue, and a bridge over North Ashland Avenue, with CY Tower on the west side at the south end of the Metra station at Clybourn (MP 2.9), which has two side platforms on the North Line, and an east side platform and center island on the Northwest Line, the lefthand running Harvard line heads northwest, Three Main Tracks, current-of-traffic, Automatic Block Signals, Automatic Train Stop, with overall speed limit 70 mph for passenger trains and 60 mph for freights, but speed restriction for diverging trains 30 mph for passenger trains and 10 mph for freights from the junction to MP 2.9, past a bridge over West Armitage Avenue, with I-90/94 still alongside to the west, a bridge over West Webster Avenue, the erstwhile location of former industrial trackage on the northeast side, a bridge over North Damen Avenue, a bridge over West Fullerton Avenue, a bridge over the intersection of North Western Avenue and West Logan Boulevard, a bridge over West Diversey Avenue, and a closed station at Maplewood on the bridge over North California Avenue.

There is a bridge over North Sacramento Avenue, a bridge over West Belmont Avenue and one over North Kedzie Avenue, the four tracks of Avondale Yard on the north side of the line, where there were once industrial spurs on the east side, a bridge over North Kimball Avenue, with North Avondale Avenue alongside to the south as I-90/94 turn away, Roscoe, where trackage on the northeast side trails back in, a bridge over I-90/94 (with the CTA O'Hare line in the median), and then running along the south side the expressway for a while, with North Avondale Avenue still alongside to the south, past a bridge over North Pulaski Road, Parkview, the Metra station at Irving Park (MP 7.0), which has two side platforms (i.e., none on the middle track), a speed restriction of 45 mph for passenger trains and 30 mph for freights between MP 7.0 and MP 7.6, a bridge over the divided West Irving Park Road (SR 19) followed by one over North Keeler Avenue, and a bridge over North Kostner Avenue at its intersection with West Berteau Avenue

The east leg of a wye once turned away south (around the north side of West Hutchinson Avenue) at Kostner Avenue, with the speed restriction dropping to 35/30 for straight trains and those going from track 3 to track 2, and 30/10 for those going between track 2 and track 1 on the crossovers at Mayfair (MP 7.8), where a former C&NW line from 40th Street Yard and Cragin trails in on the south side, and a higher speed restriction of 45/30 between MP 7.6 and MP 7.8, as the line bridges over West Montrose Avenue, and a spur to Peterson Avenue turns away north-northeast just east of the flat crossing with the double-track Milwaukee North line.