Metro and commuter rail lines around the world with express or skip-stop services.
Barcelona: L1 and Cercanias/Rodalias run parallel almost through the entire city and especially from Catalunya to Fabra i Puig.
Chicago: Red and Purple Lines are set up like New York City's Express and Local trains. There are four tracks along the corridor between Howard and Belmont. The Purple Line uses the outer tracks as an express run skipping 12 stations while the Red Line uses the inner tracks for all local stops.
Hong Kong: Airport Express Line skips some stops of the Tung Chung Line.
Kuala Lumpur: KLIA express: KL Sentral - KLIA. KLIA transit (commuter): KL Sentral - Bandar Tasik Selatan - Putrajaya - Salak Selatan - KLIA.
Kyoto: Interoperated commuter lines serve as express.
London: Metropolitan Line skips stations on Jubilee Line. Piccadilly Line skips stations on District Line, "Express" on four-track section between Wembley Park and Watford.
Madrid: Cercanias lines C2, C3, and C10 have express trains called Civis, inbound in the morning and outbound in the afternoon. On light rail line ML3 between Boadilla and Madrid, some trains skip the underused stops in between.
Melbourne: Commuter rails have express and local services.
Milan: On the Passante commuter rail, some trains have almost non-stop service in the central area, maybe even switching to long-distance tracks and going back to local tracks and service far away from the city.
Moscow: Around Moscow there are suburban lines into nine directions. Three of them have four tracks, one has three tacks, with express trains skipping some stops of the suburban trains.
Nagoya: Interoperated commuter lines serve as express.
New York: Many subway lines have both Express and Local service with three or four tracks: normally, the inner one or two are used for Express trains. Express stations are typically major transfer points or destinations. The BMT Jamaica Line (J, Z) uses skip-stop service on portions, in which two services operate over the line during rush hours, and minor stations are only served by one of the two. Details are indicated in the official MTA map. A map showing the numbers of tracks: fotkica.com.
Staten Island Railway has express service, with some trains running non-stop between New Dorp and the ferry in the mornings and between the ferry and Great Kills in evening rush (peak direction only). This is not achieved via extra tracks - it's built into the schedule.
LIRR has several Express trains during rush hours.
Osaka: Interoperated commuter lines serve as express.
Paris: RER skips stops on several routes, you have to look at the display before boarding. On RER line C, some trains have almost non-stop service in the central area, maybe even switching to long-distance tracks and going back to local tracks and service far away from the city.
Philadelphia: Broad Street Line Express. Skip-stops on the Market-Frankford Line as well with stations marked "A" or "B".
Santiago: Metro lines 2,4 and 5 have skip-stop services during peak hours. They are called either Ruta Roja (Red route) or Ruta Verde (Green route), and the trains stop only in the estaciones comunes (common stations) and the stations marked in either red or green.
Seoul: Line 9 has local and express service. There are three tracks to make the express line a real "express".
Shanghai: Line 16 has an express service that skips eight stops.
Sydney: Commuter rails have express and local services.
Tokyo: Shinjuku Line, Tozai Line, and Asakusa Line have express services.
Yokohama: Interoperated commuter lines serve as express.
[Map source: fotkica.com]: An express subways paradise, New York City has numerous multi-track lines, colour coded in this map (green=2, blue=3, red=4 tracks). Click on map preview for full-size version.
Alternating skip-stop: an alternate stopping pattern to allow for a more even passenger distribution, shorter train cycles and a (slightly) faster ride. There's a low to non-existing degree of passengers interchanging between both trains. Example: J/Z lines in New York.
Bypass: trains skip certain stations along a stretch altogether, continuing to serve stations past the domain of the local train that serves the skipped stations. Examples include the IND lines of NYC (Central Park West line, Queens Boulevard Line) or the arrangement of the parallel running Market-Frankford and trolley lines in Philadelphia between 13th and 30th Sts or the Jubilee/Metropolitan and Piccadilly/District arrangements in London. There's a low to medium degree of passengers switching between modes: only passengers on the express train wishing to go to a station served by the local (and vice versa) make a transfer.
Full local/express: two different lines, usually on their own, dedicated tracks, serve a parallel stretch where the express line only stops at major stations and the local line stops at all stations. The operation of the local line can be 'segmented' i.e.: local trains do not continue along the entire stretch; instead, different services operate between the major express stations (comparable to the local or 'stoptrein' arrangement of Dutch NS trains). Metro examples includes the IRT lines of NYC or the Broad Street Line in Philadelphia. There's a medium to high degree of passengers transferring: the express trains are meant to travel the longer distances; the local trains are meant to shuttle passengers to their final destination (and vice versa).
Like all things in the field of "metrology", this topic is as well arguable. Some arrangements look like express services at first sight, but to keep things simple and manageable, they will not be included here.
Lines that occasionally skip a few stops are not included.
Metro sections running parallel to main line rail tracks. The main line skips metro stations, but this can hardly be called an express/local metro service if the two systems have different fare structures and are not designed for easy passenger interchange. Examples: Amsterdam between Amstel and Holendrecht and between Sloterdijk and Lelylaan stations. Boston Orange and Red Lines share corridors with commuter rail.
Different urban rail lines that have some stations in common. Even when one runs much faster than the other, when they are different lines in different tunnels and interchange is not easy, they will not be counted here. Example: In Paris, the route between Chatelet-les-Halles and Gare de Lyon is served by four lines in four different tunnels (1, 14, RER A, RER D). Metro line 1 has three stations in between, the others have none.