The Chicago Subdivision or Chicago Sub is a

railroad Rail transport (also known as train transport) is a means of transport using wheeled vehicles running in railway track, tracks, which usually consist of two parallel steel railway track, rails. Rail transport is one of the two primary means of ...

line in

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...

that runs about from

Chicago Chicago is the List of municipalities in Illinois, most populous city in the U.S. state of Illinois and in the Midwestern United States. With a population of 2,746,388, as of the 2020 United States census, 2020 census, it is the List of Unite ...

Aurora An aurora ( aurorae or auroras), also commonly known as the northern lights (aurora borealis) or southern lights (aurora australis), is a natural light display in Earth's sky, predominantly observed in high-latitude regions (around the Arc ...

and hosts

Metra Metra is the primary commuter rail system in the Chicago metropolitan area serving the city of Chicago and its surrounding suburbs via the Union Pacific Railroad, BNSF Railway, and other railroads. The system operates 243 train station, stati ...

BNSF Line The BNSF Line is a Metra commuter rail line operated by the BNSF Railway in Chicago and its western suburbs, running from Chicago Union Station to Aurora, Illinois through the Chicago Subdivision. In 2010, the BNSF Line continued to have the h ...

commuter service. It is operated by

BNSF Railway BNSF Railway is the largest freight railroad in the United States. One of six North American Class I railroads, BNSF has 36,000 employees, of track in 28 states, and over 8,000 locomotives. It has three Transcontinental railroad, transcontine ...

as the easternmost part of the railroad's

Northern Transcon The Northern Transcon, a route operated by the BNSF Railway, traverses the most northerly route of any railroad in the western United States. This route was originally part of the Chicago, Burlington and Quincy Railroad, Northern Pacific Railway, ...

Seattle, Washington Seattle ( ) is the List of municipalities in Washington, most populous city in the U.S. state of Washington (state), Washington and in the Pacific Northwest region of North America. With a population of 780,995 in 2024, it is the List of Unit ...

. This line is colloquially known as The Racetrack because it is mostly triple-tracked and supports fairly fast trains. It had been operated by a BNSF ancestor, the

Chicago, Burlington and Quincy Railroad The Chicago, Burlington and Quincy Railroad was a railroad that operated in the Midwest, Midwestern United States. Commonly referred to as the Burlington Route, the Burlington, CB&Q, or as the Q, it operated extensive trackage in the states of ...

, which introduced high-speed ''

Zephyr In European tradition, a zephyr is a light wind or a west wind, named after Zephyrus, the Greek god or personification of the west wind. Zephyr may also refer to: Arts and media Fictional characters * Zephyr (comics), in the Marvel Comics univers ...

'' passenger trains in 1934 and ran many of them along this subdivision from Chicago to points west. The Chicago Subdivision meets the Aurora Subdivision and

Mendota Subdivision Mendota can refer to any of the following places in the United States: * Mendota, California * Mendota, Illinois, a city in LaSalle County * Mendota Township, LaSalle County, Illinois * Mendota, Minnesota * Mendota Heights, Minnesota * Mendota, Vi ...

in Aurora. Commuter service ends at the Aurora Transportation Center, though

Amtrak The National Railroad Passenger Corporation, Trade name, doing business as Amtrak (; ), is the national Passenger train, passenger railroad company of the United States. It operates intercity rail service in 46 of the 48 contiguous United Stat ...

trains continue southwest on the Mendota Subdivision. Triple-tracking runs from where track leading to the Aurora station and Metra Yard joins the subdivision eastward to

Cicero Marcus Tullius Cicero ( ; ; 3 January 106 BC – 7 December 43 BC) was a Roman statesman, lawyer, scholar, philosopher, orator, writer and Academic skeptic, who tried to uphold optimate principles during the political crises tha ...

, where multiple tracks from a yard join. It is then quadruple-tracked for the rest of the way until the turn to

Union Station A union station, union terminal, joint station, or joint-use station is a railway station at which the tracks and facilities are shared by two or more separate railway company, railway companies, allowing passengers to connect conveniently bet ...

. weekday traffic on the subdivision was 94 Metra commuter trains, eight Amtrak intercity trains, and 60 BNSF freight trains. After the introduction of the CB&Q ''Zephyrs'', train speeds increased significantly around the country for the next decade or so, but the

Naperville train disaster The Naperville train disaster occurred April 25, 1946, on the Chicago, Burlington and Quincy Railroad at Loomis Street in Naperville, Illinois, when the railroad's '' Exposition Flyer'' rammed into the ''Advance Flyer'', which had made an unsched ...

along these tracks in 1946 was one event that contributed to the federal government restricting speeds in later years. Trains that had once traveled at or above were soon restricted to a maximum of . Much of this line has a speed limit of for passenger trains, while freight trains run slower.

Passenger Services

* ''

California Zephyr The ''California Zephyr'' is a Amtrak Long Distance, long-distance passenger train operated by Amtrak between Chicago, Illinois, Chicago and the San Francisco Bay Area (at Emeryville station, Emeryville), via Omaha, Nebraska, Omaha, Denver, Sa ...

'' * ''

Southwest Chief The ''Southwest Chief'' (formerly the ''Southwest Limited'' and ''Super Chief'') is a Amtrak Long Distance, long-distance passenger train operated by Amtrak on a route between Chicago and Los Angeles through the Midwest and American Southwest ...

'' * ''

Illinois Zephyr and Carl Sandburg The ''Illinois Zephyr'' and ''Carl Sandburg'' are a pair of passenger trains operated by Amtrak on a route between Chicago and Quincy, Illinois. As ''Illinois Service'' trains, they are partially funded by the Illinois Department of Transporta ...

References

External links

* {{Commons category-inline
BNSF Subdivisions
BNSF Railway lines Rail lines in Illinois