Madrid is the twenty-fifth most populous area in the world, yet it has one of the most extensive public transit systems in the world, and it is still expanding. The subway, which is called the Metro, opened in 1919 and now has (as of 2015) 301 stations. There are thirteen lines on the system (twelve plus a branch line). A total of 560.9 million passengers rode the Metro in 2014. The Metro has a varied fleet with all the current equipment being built by CAF or Breda. All Metro lines have the same track gauge, however, the width of the rail cars on the different lines varies. Narrow profile lines have trains that are 2.3 meters wide and the trains on these lines are up to 90 meters long (6 cars); the narrow profile lines are lines 1, 2, 3, 4, 5, and the branch line. Wide profile lines have trains that are 2.8 meters wide and up to 115 meters long (also 6 cars long); the wide profile lines are lines 6, 7, 8, 9, 10, 11, and 12. However, Line 11 is temporarily being operated with narrow profile stock until the line is substantially complete and the ridership levels warrant larger trains. Platforms have been extended temporarily so there isn’t a significant gap between the platform edges and the trains on this line. All trains have air conditioning, and most trains have electronic displays that show the next stop and which side the doors will open on and automated announcements. Newer trains come in multi-car trainsets with articulated joints between each car, allowing for unobstructed passage throughout the entire train (or most of it, depending upon the car type). Service is frequent throughout most of the day, with trains running every 2 to 5 minutes from 6 AM until about 9 PM. Service is less frequent from that time until closing at 2 AM. The Madrid Metro also has 1,698 escalators, more than any other subway in the world:
In 2007, after four years of construction, Madrid opened its first three light rail lines. These lines are operated by Metros Ligeros de Madrid, S.A., a subsidiary of Metro de Madrid, with a fleet of Alstom Citadis 302 trams. There are plans to construct additional light rail lines in addition to expanding the Metro system.
Madrid also has Spain’s largest bus system, operated by Madrid Municipal Transport Company, S.A. The fleet has just over 2,000 buses operating on 209 routes. In 2006, over 500 million passengers used the bus system, and the buses traveled over 62 million miles (100 million kilometers). The fleet includes buses powered by diesel, compressed natural gas, hydorgen, and hybrids.
There are two subsets within the 2000 Series cars, which make up the bulk of the rolling stock for the narrow gauge lines. The 2000A Series cars are boxier and very numerous, with 530 cars being delivered between 1985 and 1993. Some are being retired and replaced with 3000 Series cars, with the remainder to be refurbished and remaining in service on Line 1 indefinately. The 2000B Series cars are nicknamed burbujas (Spanish for bubble) due to their rounded head ends. There are about 126 of these types of cars, built in 1997 and 1998, and running on Line 5 with no plans to be retired at this time.
The 3000 Series is the first narrow profile train type to come in fully articulated trainsets. The 3000 Series operates on lines 2, 3, 4, 11 and the branch line and comes in trainsets with 4 cars for use on lines 2, 4, and the branch line and 6 cars for use on lines 3 and 11. The 3000 Series has many of the same features as the 8000 Series wide profile stock, but a slightly different interior color scheme.
The 5000 Series cars are the oldest currently in operation on the Madrid Metro, with the oldest subseries dating back to 1974. The series has several subserieses, with the last one being delivered in 1993. Currently, the 5000 Series cars can be found on Line 6. They are boxy in their design, like the 2000A Series. They are also the only Madrid Metro cars to not have passenger operated doors. As the number of 9000 Series cars increases, the 5000 Series cars will be retired.
The 6000 Series cars were delivered in 1998 for service on Line 9. These were the first Madrid Metro cars to have an articulated joint allowing for passage between train cars without needing to exit the train. However, the 6000 Series cars only had one articulated joint in each pair of cars, meaning that the trains are in married pairs and not complete six car trainsets. The 6000 Series also featured suburban style seating for passengers traveling on the suburban section of the line to stops between Puerta de Arganda and Arganda del Rey. These were also the first Madrid Metro cars to have exterior destination signs and electronic run number signs. The reason for this was that Line 9 was the first line with multiple segments so it was considered helpful to display the destination on the train's exterior. These trains also operated on Line 7. In 2013, 73 of the 108 6000 Series trainsets were sold to the Buenos Aires Underground for use on that system's Line B. As of 2018, the 6000 Series cars that remain in Madrid operate on Line 9 between Puerta de Arganda and Arganda del Rey.
The 7000 Series cars were the first Madrid Metro cars ever not built by a Spanish manufacturer. They were also the first cars to come with articulated joints allowing for unobstructed passage through an entire 6 car train (the 6000 Series was the first train to have articulated joints between the cars, but the cars were still in married pairs). Additional features include interior TV screens that could display information, but these are not currently used for any purpose. The 7000 Series cars can be found on Line 10 and also at times on Line 6.
The 8000 Series was delivered in 2002. Today, they operate on lines 8 and 12, and occasionally appear on lines 6, 9, and 10 as well. These trains were the first Madrid Metro cars to have regenerative braking. They also feature lights to alert passengers that the doors are about to close, a fire detection and suppression system, backup emergency lighting, lateral evacuation ramps, digital radio communications, aluminum bodies, an aerodynamic design, full front cab window, computerized information displays, and closed circuit television, etc. Some of the trains on Line 8 have a special compartment for transporting luggage from the Nuevos Ministerios station to the airport.
The 9000 Series cars were the second group of cars to be purchased from Breda. In addition to all the same features that 7000 Series cars have, these cars have enhanced access for disabled passengers and warning lights to alert passengers that the train doors are closing. These cars can be found on Line 7 and the Tres Olivos-Hospital Infanta Sofía section of Line 10. The next batch to be delivered will operate on Line 6, replacing the 5000 Series cars which are the oldest in the system.
The Madrid Metro has 300 stations. The architectural design of each station usually indicates its age. Most stations are underground with side platforms, but there are a few stations that are above ground and a few stations have island platforms. The "Spanish Solution" to facilitate boarding and alighting is in use at busy interchange stations, such as Cuatro Caminos and Avenida De América.
In 2007 following four years of construction, Madrid opened its first three light rail (tram) lines. The first line, designated ML1, opened on May 24, 2007. It operates in Northern Madrid, connecting Pinar de Chamartín on Metro lines 1 and 4 to Las Tablas on Line 10 on a 3.36 mile (5.4 kilometer) route with 9 stops. On July 27, 2007, lines ML2 and ML3 opened. These lines start at the Colonia Jardín station on Line 10 and operate to destinations in southwestern Madrid. All three tram lines use Alstom Citadis 302 trams and are operated by Metros Ligeros de Madrid, S.A., a subsidiary of Metro de Madrid. A fourth line is currently under construction as of 2015.