The Purple Line of the Chicago "L" is a route on the northernmost section of the system. The service begins from station in Wilmette, north of Chicago, and ends at station in the Rogers Park neighborhood on Chicago's North Side, along the way making various stops at stations in the city of Evanston.
During weekday morning and afternoon rush hours, the Purple Line extends another south on the North Side Main Line, making its entire run in rush hour from Howard to Downtown Chicago. During these periods, the line runs express from Howard to , then express from Wilson to , then making all local stops from Belmont to the Loop. The express service is known as the Purple Line Express (or the Evanston Express).
In 2024, the average weekday boardings on the Purple Line was 4,904. It is the shortest route in the CTA rail system except during weekday peaks and rush hours.
Prior to the color-coding of CTA rail lines in 1993, the Purple Line was known as the Evanston Line, Evanston Service or Evanston Shuttle, and the Purple Line Express was called the Evanston Express. Internally, it is still referred to as the Evanston branch, with the Loop-bound service referred to as the Evanston Express.
The Purple Line is useful for reaching Northwestern University ( and stops in Evanston), including the sports facilities Ryan Field, Rocky Miller Park, Welsh-Ryan Arena, and Canal Shores Golf Course — all at the stop — and the Bahá'í House of Worship at . The selection of purple as the line's color was likely from Northwestern's official school color.
Operation Trackage Beginning at Linden Avenue in Wilmette, which contains a small storage yard and car service shop, the Purple Line traverses the North Shore area on private right-of-way which begins at street grade. Running southeasterly from Wilmette, the line rises past Isabella Street on the Wilmette-Evanston border, then bridges the North Shore Channel immediately north of Central Street, the first stop in Evanston. The line, now on an elevated embankment, curves southward parallel to Sherman Avenue. Continuing south, the line enters downtown Evanston and stops at Davis Street, then curves southeasterly again to parallel Chicago Avenue and Metra's Union Pacific Railroad right-of-way to just north of the CTA's Howard Yard facilities.
Here the line crosses through the yard area before the junction with the Red Line and the Yellow Line. The tracks are split on grade-separated structures to allow Yellow Line trains to enter the junction from the west. Immediately south of the yard lies the Howard Street terminal, where Red, Purple and Yellow Line trains all terminate.
There are four operational tracks starting at Howard Street, continuing southward to . During weekday rush hours, the Purple Line runs express on the outer tracks, skipping all stops until Wilson Avenue, and then to Belmont Avenue. From Belmont Avenue to Armitage Avenue, the Purple and Brown Lines share the outside tracks and both make all stops along the route. From just south of Armitage Avenue to just north of Chicago Avenue, they are on a two-track line on a 4-track structure. After the North Shore Line ceased operations in 1963, the outer tracks in this area were rarely used and received next to no maintenance; they were permanently taken out of service in 1976.
Routing
The original routing of the Purple Line Express was clockwise around the Inner Loop track via Lake-Wabash-Van Buren-Wells, making all Loop stops before returning to Merchandise Mart and making all stops northbound to Linden. Beginning April 2, 2007, the Purple Line Express was rerouted onto the Outer Loop track along with the Brown Line due to the construction at the Belmont and Fullerton stations (see below). Prior to this, Purple Line Express trains were occasionally diverted to the Outer Loop track in the event of emergencies or signal problems in the Loop. On December 4, 2008, the CTA announced that the Purple Line Express would return to the original Inner Loop routing on December 29.
If a problem occurs on the North Side Main Line between the Loop and the Fullerton station, the Purple Line is generally routed into the State Street subway, following the Red Line to before returning north.
For several years, inbound afternoon Purple Line Express trains stopped at before weekday evening Chicago Cubs baseball games, in order to provide direct service to Wrigley Field for passengers coming from northern Chicago, Evanston and Skokie. However, because of a platform reconfiguration in the early 1990s, trains had to cross over to the inner Red Line tracks, as there is no platform access to the outer tracks at Addison. As a result of the Brown Line construction and in an effort to minimize delays, Purple Line Express trains in some years stop at — one station north of Addison — before evening Cubs games. (That station was constructed with two island platforms that can access the express tracks, eliminating the need for trains to switch over.) Depending on the year, either Addison or Sheridan has this extra stop. For example, in 2024 the additional stop for Cubs home games was at Addison, while in 2025 it was at Sheridan.
Connections The Purple Line Express, which operates only on weekdays during rush hours, is one of only two 'L' lines to offer transfers to every other line, the other being the Red Line. It is also the only 'L' line to provide non-farecard transfers to every other line (the Red Line does not provide a non-farecard transfer to the Pink Line).
The Purple Line stations at and are immediately to the east of their Metra counterparts, while the , , and stations on the express leg are within walking distance of Metra trains at Ogilvie Transportation Center, Union Station, LaSalle Street Station and Millennium Station, respectively.
Rolling stock , the Purple Line operates with the Bombardier-built 5000-series railcars. Until late May 2014, 2400-series cars were also assigned to the line and, for the entire 2000s and early 2010s, the Purple Line fleet consisted entirely, or nearly entirely, of 2400-series cars. In spring 2007, a small number of 3200-series railcars were transferred to the line, replacing the 2600-series railcars transferred to other lines. Those 3200-series cars have since been returned to their originally assigned lines. The 2600-series cars were officially assigned to the line until early January 2013 when they were transferred to the Red and Blue Lines.
Beginning in October 2013, the CTA started to reassign the 2600-series cars back to the Purple Line as new Bombardier-built 5000-series cars were deployed to the Red Line. Then, beginning in April 2014, CTA started to assign Bombardier-built 5000-series cars to the Purple Line. In May 2014, the last 2400-series cars on the line were removed from service. In March 2015, the 2600-series cars on the line were also removed from service. The Purple Line typically runs with six cars, occasionally borrowing cars from the Red Line as needed to fill shortages.
Operating hours and headways The Purple Line operates full-time between Linden and Howard from Mondays to Thursdays from 4:25 a.m. to 1:30 a.m., Fridays from 4:30 a.m. to 2:10 a.m., Saturdays from 5:05 a.m. to 2:15 a.m. and Sundays from 6:05 a.m. to 1:45 a.m. On weekdays, frequencies consist of 12 tph (trains per hour) during rush hours, 6 tph during middays, then 4–5 tph during the evening and 3 tph after midnight. On weekends, service operates 4 tph early morning and night and 5 tph and late afternoons.
The Purple Line Express operates rush hour service between Linden and the Loop on weekday morning only from 5:15 a.m. to 9:20 a.m. (southbound) and from 5:55 a.m. to 10:05 a.m. (northbound). On weekday evenings, service resumes from 2:25 to 6:25 p.m. (southbound) and from 3:05 p.m. to 7:05 p.m. (northbound), with headways of five to eight minutes (with wider headways of 15 minutes possible).
History
The Northwestern Elevated era The Evanston Line went into operation on May 16, 1908, between Central Street, Evanston, and the Loop when the former Northwestern Elevated Railroad extended its mainline service over leased electrified steam railroad trackage owned by the Chicago, Milwaukee, St. Paul and Pacific Railroad. On April 2, 1912, the line reached its present-day terminal at Linden Avenue, Wilmette. The new terminal was established without the permission of Wilmette residents, who feared rail service would encourage construction of large apartment buildings in the affluent community.
In 1922, the surface-level section of the North Side 'L' was elevated onto a concrete embankment between Leland Avenue and Howard Street and was expanded from two to four tracks, allowing complete express service from Wilmette and Evanston to downtown Chicago. Several segments of the Evanston Branch itself ran at street level until 1928, when a section between Church Street and the North Shore Channel was elevated onto a concrete embankment. It went into operation on October 5, 1928. Nine stations existed north of Howard, including a station at Calvary. That station closed in 1931 and was replaced by a new station at , to the north.
CTA era
The service which was to become the Purple Line was transferred to the Chicago Transit Authority along with Chicago's other rail transit services on October 1, 1947. The current service pattern went into effect on July 31, 1949, after a massive service reorientation on the North–South rapid transit system. Local service, operating between Linden Avenue and Howard Street, ran at all times. The express service ran only during weekday rush hours, stopping at all stations in Wilmette and Evanston, plus , (formerly Rogers Park), , , Chicago/Franklin, and all elevated Loop stations. While skip-stop service was also introduced at this time, Evanston express trains continued to make stops at all these stations. An express surcharge was also instituted for customers traveling to and from the Loop north of Howard. Several attempts were made to reduce or eliminate the additional fare, backed by local politicians.
Right-of-way and trackage used by the Evanston Branch and the North–South Route (today's Red Line) between Leland Avenue and the Wilmette terminal was purchased by the CTA in 1953 from the Chicago, Milwaukee, St. Paul and Pacific Railroad. In turn, the railroad received US$7 million in CTA revenue bonds.
Midday and Saturday Loop express service was discontinued in the 1950s and the local shuttle service began using one-man operations with single unit cars in the 1960s.
On July 16, 1973, the station closed, bringing the total number of stations on the Evanston branch to eight.
On November 8, 1973, the third-rail electrification system was installed on the Evanston Branch between in Evanston and the Wilmette terminal. Prior to this, Evanston shuttle trains had to be equipped with trolley poles that collected power from overhead catenary wires (similar to the Yellow Line before its conversion to third-rail power in 2004). The third-rail conversion allowed the CTA to retire the 4000-series cars, which were nearly 50 years old, and put newer cars on the line. Since parts of the line are at grade level, some in the community initially resisted the conversion, worrying that the proximity of the rail would prove hazardous.
By the end of 1976, the Evanston Express ran nonstop between Howard and Merchandise Mart, no longer stopping at Morse, Loyola, Wilson or Chicago/Franklin. The CTA cited complaints about service delays due to the extra stops as justification for the changes.
However, on January 20, 1989, express trains once more began making additional stops outside the Loop, at the Belmont and Fullerton stations, in order to relieve overcrowding on the rapidly growing Ravenswood branch (now the Brown Line). By the end of the 1990s, trains would make all stops between Belmont and the Loop.