Alicante

Alicante's rapid transit system is called TRAM, which is a train-tram and is operated by FGV, owned by the Valencian regional government. This system has an underground line in the city center, with three stations on it. The layout consists with one or two mezzanines on level -1 and two side or one island platforms at level -2. Luceros and Mercado stations have direct connection with the underground parking lots, which are located above the TRAM tunnel.

Amsterdam

Metro services in Amsterdam can be grouped in two groups. The North-South line (in Dutch, Noord/Zuidlijn) opened recently and M52 services run on it. The central part of the line is underground, running at a considerable depth with two parallel tunnels. The other group of lines consists of services M50, M51, M53 and M54. This line runs mostly overground or elevated, parallel to the Dutch Railways lines. In the city center this line goes underground but at a small depth.

Most of the underground stations consist of a mezzannine at level -1 and a island platform at level -2. The vast majority of overground and elevated stations also have island platforms, but the hall where the turnstiles and ticket machines are found is located on the ground level.

Taking into account that most of the metro network runs parallel to rail lines, transfers between these two modes of transport are quick and easy.

Antwerp

The Antwerp premetro (underground tramway) opened in 1975. One of the achievements consisted in linking both banks of the Scheldt river.

Despite the tram network being huge, the Premetro is short but complex. Lines can be grouped in two. The first group consists in an east-west line with two branches on the eastern side. However, there is a tunnel allowing services between both branches, thus forming a triangle. The second group of lines consists in a tunnel opened in 2015, connecting the city center with the eastern suburbs with a fast service, since most of stations are not opened yet.

The Central railway station is linked with Astrid and Diamant premetro stations, and together with an underground bike parking, they form a hub. The rail triangle is located in between those two stations. Since the premetro tunnels were built with metro standards, same-level track crossings are not allowed, therefore Astrid and Diamant stations had to be built with platforms at two different levels.

Barcelona

Barcelona is the queen of the long passageways. Until 1995, all transfer stations consisted of corridors with lenghts over 100 m, except for Sagrera and Catalunya.

Among the reasons for having such long corridors there is the lack of planning or the vision of the metro network as a bunch of individual lines. As an example: line 1 and line 4 were extended to Urquinaona in 1932, but both lines were not connected until 1972, as they were originally operated by different companies. In Plaça de Sants station, the L5 platforms were built as close as possible to the existing ones from L1, which opened 43 years before. However, there is a gap of 150 m, with the national rail tracks located in between.

Moreover, since the extension of the metro network was slower than the growth of the city, during the 60s and 70s, transfer stations were built 100-150 m apart, in order to increase the accessibility to the metro. Verdaguer is a good examples of this practice.

Right after 1980, transfer stations were designed in a more proper way, being the L2 stations the best example. A new type of transfer appeared 15 years ago with the extension of the metro towards hilly areas of the city: the vertical transfers. In those stations (eg: Vall d'Hebron, Fondo, Zona Universitària, Collblanc), a big shaft was built in order to fit either high-capacity lifts or series of escalators to reach the platforms.

The classic layout of metro stations in Barcelona is simple: on level -1 there is one or two mezzanines and in level -2 there are two side platforms, but since 2000 the new stations tend to have a central plafrom instead. In transfer stations, there is tipically a corridor linking the mezzanines of both lines.

Mandatory to mention the so-called Barcelona solution or Spanish solution: stations with two tracks and three platforms, where passengers alight using one platform and board using the opposite one, improving the flow of passengers and reducing the dwell time. Barcelona was not the first city to implement it, but it was named after most of the stations built in the 30s, 40s and 50s were designed with such layout.

Berlin

The U-Bahn and the S-Bahn are the two rapid transit systems of Berlin. The city-state owns the first and the German railways own the second. The S-Bahn normally runs overground or elevated and the U-Bahn does it underground, as the name suggests in German, but this is not a norm since some parts of the U-Bahn are elevated and vice versa.

The oldest lines were built either in elevated sections or underground, but very close to the surface, creating a direct connection between the street and the platforms in most of the cases. The lines built after World War I are a bit deeper, in order to fit mezzanines and corridors between the street and the platform levels.

Transfer stations have a very easy tolopolgy, since stations are located close to the ground level and island platforms are predominant.

Bilbao

Despite the metro opened in 1995, its layout follows former metric-gauge rail lines that were converted to metro, such as the Bilbao - Plentzia line. Metro Bilbao operates lines 1 and 2 and Euskotren operates line 3, together with other suburban and regional services.

Due to the orography of the city, stations may have different layouts. The stations located in the city center are deep, since the Nerbion river is located nearby and there are plenty of hills located in the meanders of the river. The stations of the line 1 branch are located on surface, since they were part of the former Plentzia railway.

Line 3 benefits from having already existing stations, such as Bilbao-Aduana (currently called Zazpikaleak/Casco Viejo) and Matiko, both part of the former Plentzia line, despite the connection between those two stations is made through a new double-track tunnel.

Some transfer stations have effective designs, such as Lutxana or the former Bolueta station.

Boston

All the rapid transit lines in Boston are centenary. Three of them originally opened as underground tramway tunnels in downtown Boston, but only two were converted to pure metro lines. The Green line is still an underground tram line.

Most of the downtown stations are quite unusual, as they were built using early construction methods and most were designed to serve as tram stations. For instance, some stations in the Orange line have offset platforms. At State station, the Orange line platforms are in different levels.

Underground stations tend to be located close to the surface. This can be appreciated at Government Center, where the Green line platform has a very particular shape because the streets located above ground were quite narrow when the line was constructed, and therefore impossible to dig wider tunnels.

Despite being a city where the rapid transit lines were built without a network plan, transfer stations have a good layout, providing short and quick connections.

Brussels

The Brussels metro is a good example of a planned system. It was planned in the 60s, and the four existing lines were built following this criteria: if for practical reasons, the section to be opened was not long enough to be operated as a metro line, the section would open provisionally as a premetro (underground tram), with temporary low floor platforms and temporary ramps connecting the streets with the tunnel. Once the construction of the line is advanced, the premetro operation is cut and the line is converted into a full metro line, removing the ramps and elevating the platforms to metro standards. Currently lines 1, 2, 5 and 6 are fully metros and lines 3, 4 and 7 are premetros.

The whole network has been built following the same plan. Transfer stations have a good design as well, with the notable exception of Dè Brouckère, where there is a long corridor. Cross-platform transfers can be found in Beekkant and Gare du Midi. Arts-Loi, Montgomery and Rogier have crossing interchanges.

Most stations have side platforms located at level -2, whilst level -1 is reserved for mezzanines. Stations on line 6 have island platforms because trains run on the left side instead. Stations on lines 3/4 were built using the Spanish solution, where passengers board using the island platform (except in Gare du Midi).

In order to reduce fare evasion, most stations have been equipped with turnstiles during the last decade, replacing the existing honor system which is still present in some stations due to the complexity of its layout.

Budapest

Budapest was the first city in continental Europe to have a metro. Line 1 opened in 1896. Similar to other systems opened around 1900, tunnels have a narrow profile. Trains are only 2.60 m high and 30 m long.

Lines 2 and 3 have a similar style to other Eastern European metros, despite the decoration has nothing to do. Line 4 was built recently. In these three lines, tracks are laid in two parallel tunnels that cross Budapest at a considerable depth. Stations have island platforms in two parallel galleries, which are connected with the ticket hall through a long escalator. The ticket hall can either be located at ground level or just underground. In the latter case, there are direct staircases connecting the hall with the tramway platforms or bus stops.

The northernmost and southernmost parts of line 3, tracks run underground but at a very little depth. Here stations have side platforms, which are located at level -2 (and a mezzanine at level -1) or directly at level -1, together with an independent booking hall for each direction.

Transfers differ, depending on the station. In Deák Ferenc Tér and Kálvin Tér, transfers consist in a quick connection through two escalators and a short corridor. In other stations, transfers may be longer since one line might be running close to the surface while the other may be running very underground (eg: Keleti pályaudvar, Batthyány tér)

Bucharest

The Bucharest metro consists of 5 lines, despite lines M1 and M3 share their tracks and line M5 has two branches. The original plan from the 70s consisted of three lines: a east-west line (M3 and southern section of M1), a north-south line (M2) and a circle line circa 40 km long.

Unlike other Eastern European metros, the Bucharest one was not built at a considerable depth but using cut-and-cover methods. The platforms are typically located at level -2 or -1 and tend to be central, despite some stations in line M1 have side platforms.

Buenos Aires

The Subte is the oldest metro network in Latin America. It consists of 6 lines. 4 of them run east-west (A, B, D, E) and the other two are north-south (C, F).

The entire network runs underground and except for line H, the tunnels were build close to the surface. Most of the stations have side platforms but those stations that are or had been terminus usually have island platforms.

The lower level of an average station comprises the platforms. If there is enough space between the platform level and the street level, a mezzanine can be found, containing the ticket booths and turnstiles. In the opposite case, each platform has independent accesses and turnstiles are located at the platform level and there are no overpasses or underpasses.

The Subte applies a bizarrenaming criteria. Station names are independent for each line. So, a transfer station will have multiple names, one for each line calling at it (eg: Pueyrredón (B) and Corrientes (F) are part of the same station). But there is also the opposite situation, where there are stations with the same name in different lines: Callao and Pueyrredón are four stations located in lines B and D, but they have nothing to do.

Copenhagen

Copenhagen has a modern and automatic metro. Both the Metro and the S-tog have an honor system and most underground stations look like the same: mezzanine with vending machines at level -1, a landing at level -2 and island platforms at level -3. The connection between the platform and the mezzanine is provided by lifts and escalators. Upbound escalators are separated from the downbound ones.

Transfer corridors are connected to mezzanines in Frederiksberg and Kongens Nytorv, but not in Nørreport, where the corridor heading to the S-tog starts at the end of the Metro platform.

Frankfurt

Despite Frankfurt has officially a U-Bahn (pure metro), technically is a Stadtbahn (light rail), despite the platform level is high even for stops located at the street. The S-Bahn is also part of the basic rail network of the city.

The main transportation hubs were desinged to provide quick transfers between the rail lines. Most transfer combinations involve passing through a staircase or an escalator, but in Hauptwache, a cross-platform is provided for transfers between S-Bahn and U-Bahn lines U6 and U7.

Glasgow

Glasgow has a very peculiar subway. It opened in 1896 as a circle line powered by cable, like the San Francisco cable cars. The subway was fully renovated between 1977 and 1980 in order to change its operation to electric power, build new workshops, relocate stations and refurbish the rest of stations.

Before the renewal, all stations had a very narrow island platform. A staircase located at the end of one platform lead to the ticket hall and the exit, typically located inside the station building. Most of the stations retain this layout today. However, escalators have been installed in some stations, to connect the ticket hall with the street. The stations with the highest patronage were completely rebuilt: Buchanan Street has a central and a side platform nowadays. In St Enoch, two side platforms replace the former island platform. Partick station was built during the renewal works in order to allow transferring from the Subway to ScotRail.

Hannover

Hannover has a Stadtbahn, which is a mixture of a tramway that runs in a metro-like tunnel in the city centre.

There are three trunk tunnels in Hannover (A, B, C) that meet in Kröpcke station. Tunnels B and C run overlapped between Kröpcke and Aegidientorplatz.

The layout of an average station is simple and similar to the ones in other cities: a mezzanine at level -1 and side platforms at level -2.

Kröpcke station is a huge complex with lots of accesses, escalators, staircases and mezzanines, since is the only point where the three tunnels meet. Hauptbahnhof station (main station) has elevated rail platforms and an underground station for the Stadtbahn, composed of two island platforms and four tracks. Aegidientorplatz station has a peculiar layout, since the mezzanine is at level -1, the northbound platform is at level -2 (with 2 tracks) and the southbound platform is at level -3 (with 2 tracks as well).

Lyon

The four lines of the Lyon metro are technically different. Lines A and B and D are rubber tired. Line A has manual conduction and line D was already opened with automatic trains. Line B switched from manual driving to automatic operation in 2022.

Line C partially follows the route of a former funicular that had a pent of 176‰. Therefore it operates as a rack railway between Hôtel de Ville and Croix Rousse, since normal metro lines have a maximum pent of 40‰.

Lines A and B run at a very little depth. Even line A crosses the Rhone using the box girder of Pont Morand. The stations of this line only have one underground level, with side platforms and turnstiles on it. Some stations have underpasses, connecting both platforms. Line D tunnels are not located deep either, but most stations have a mezzanine between the street and platform levels. The latter situation also occurs in the eastern section of line A.

Lyon had an honor system until two decades ago. Since some staion have secondary accesses connecting the streets with the platform, it is common to find turnstiles in the platforms.

Most of the transfer stations have an efficient layout, such as Hôtel de Ville, Saxe-Gambetta or Charpennes. However, the links between at the two main railway stations (Part-Dieu and Perrache) are long.

Lisbon

Currently the Lisbon metro consists of four lines. Until the mid-90s, the network had a Y-shaped single line. This line was split into three (Blue, Yellow and Green) and the Red line was built as a completely new line. Therefore, all the internal metro transfers are less than 25 years old.

The layout of the stations differs slightly: Baixa-Chiado and Campo Grande have parallel platforms for the two lines serving the stations. Saldanha, São Sebastião or Oriente allow quick transfers that involve climbing stairs or elevators. However, in Alameda or Entre Campos the transfer consists in a long passageway.

The standard layout for the stations built before the Carnation Revolution consisted in two side platforms at level -2 and a mezzanine at level -1. These stations featured short platforms, that were extended years later to allow 6-car trainsets. Together with these platform extensions, secondary mezzanine and accesses were added. The stations built recently tend to have a single mezzanine and are located at deeper, since they were built in hilly areas.

London

The London Underground (or the Tube) is the oldest in the world and it consists of two different networks: the sub-surface lines (running close to the surface) and the deep tube lines (runing deep, with tunnels that ressemble a tube).

The sub-surface lines are the ones inherited from the Metropolitan Railway and from the District Railway, two lines built using cut-and-cover methods or running elevated or at ground level, which were steam operated until the early 20th century. Stations consists in a building located at ground level, containing the ticket offices and fare gates, and the platforms placed at level -1. The stations were located inside a block of houses whenever possible and most of them had a canopy (still in place in Paddington, Bayswater or Earl's Court). With the electrification of the tracks and real estate speculation, most of the stations have been covered with concrete labs (such as in Gloucester Road or Mansion House).

The deep tube lines began to be built in the last decades of the 19th century, when the boring methods were a bit developed. They were already planned to be operated with electric trains. The tunnels were bored at a depth of 20 m and until the construction of the Victoria Line, they followed the streets. Stations consists of a building hosting the ticket offices and the fare gates, which are connected with the platforms (most of them are island platforms) via lifts and spiral staircases located inside of shafts. In 1913 an escalator was installed at Earl's Court as part of a test to replace lifts. Since the result was favorable, the practice of building stations with lifts and spiral staircases in shafts was abandoned. From this moment on, the new stations were built with escalators, and the existing ones (especially those with a high ridership) were transformed.

Initially each line was operated by a different company, so transfers between lines weres not granted. This was corrected after the nationalisation of the Tube.

Some stations host huge flows of passengers. This obligated the local authorities to build wider or newer passageways and escalators in some transfer stations. That is the reason some transfer stations have one-way corridors as well, such as in Oxford Circus or Victoria.

Madrid

technically, the Madrid metro lines can be divided into two: the narrow profile lines (1-5 and the Ramal) and the wide profile lines (6-12). The narrow profile lines were the first to be built and were inspired by the Paris metro. That is why old stations have side platforms located at level -2 and one mezzanines at level -1. Decades after the opening, lines 1 and 3 got their platforms extended from 60 m to 90 m long and secondary mezzanines and accesses were added.

The lines with a wider profile were built with the aim of fitting larger trains and larger stations. Moreover, these lines were built a highest depth in comparison to the narrow profile lines, at a depth of 15 to 25 m below surface level. The streets and the platforms are connected through 3 to 5 series of staircases and escalator, with the ticket hall in between. Therefore, access times are longer compared to narrow gauge lines.

Since the 90s, the design and layout of new stations have been standadrised, with stations being built using cut-and-cover methods with slurry walls.

Madrid has plenty of different layouts for transfer stations. In comparison with other cities, Madrid has a great amount of stations containing long corridors, but not at the level of Barcelona.

Possibly the most prominent stations are the macrohubs built in the first decade of the 2000s, with huge mezzanines, wide staircases and lots of lifts and escalators, allowing quick connections between metro, commuter train and interurban buses as well. The best example is Nuevos Ministerios, but Chamartín, Sol, Príncipe Pío, Plaza de Castilla or Moncloa also need to be mentioned.

Marseille

The Marseille metro is formed by two lines that cross themselves in Saint-Charles and Castellane, both located in the city centre. The links between lines in these two stations are quick, since in Saint-Charles line 2 is between the two tracks of line 1 and in Castellane both lines have their platform very close to the intersect point.

There are three kinds of stations, according to their layout: the suburban, which are elevated (eg: Bougainville, Ste-Margueritte, La Rose); the underground ones close to the surface, with the ticket hall at level -1 and side platforms at level -2 (eg: Baille, Périer); and the deep centric stations, which have island platforms and a single access consisting of long escalators connecting the street level with the mezzanine (eg: Cinq Avenues, Estrangin).

Noailles station is the most particular since the former tram tunnel was diverted when metro line 2 was built. Currently the former tunnel serves as a passageway, and the former tram terminus is a ticket hall.

Milan

Line 1 opened in 1964 and was the first metro line in the world to be built using slurry walls. Line 2 opened four years, following the same design standards for line 1. Stations have a very functional layout, since passenger flows were seriously taken into account. Almost all stations have one-way staircases connecting the side platforms (located at level -2) and mezzanines (at level -1): one for passengers entering and another for passengers alighting.

The same concept was latter aplied to lines 3 and 5, opened decades later, despite both having a radically different design in their stations, compared to lines 1 and 2. Most of their stations also have mezzanines at level -1 and side platforms at level -2.

Engineers opted to superimpose the tracks in the central section of line 3, where tracks follow the narrow streets of the old city. As a result, the stations of this sections are a maze of lifts, one-way staircases and escalators, combined with a peculiar decoration.

The transfers are typically short and quick, especially in Loreto, Centrale, Cadorna and Repubblica. The only two stations having long corridors are Lotto and Porta Venezia.

Paris

The Paris Metro has the most labyrinthine interchanges in Europe.

Almost all the metro network was opened before World War 2. The first transfer stations, opened in the early 1900s, had simple transfers, with bidirectional passageways. Since 1920, the company responsible for the metro began to install portillons automatiques (automatic doors) in some stations. The portillons automatiques are doors located at the entrance of a platform, that blocks the access to it once a train enters the station, in order to reduce the dwell time and prevent last-second passenger boarding the trains. Therefore, in order to limit the access to platforms but not the exits, they decided to build two-directional corridors and staircases. That is how the stations began being underground mazes.

In the 1970s the RER (suburban railway) was opened. This meant that some metro stations had to be partially rebuilt.

Taking the advantade that the spacing between stations is one of the lowest in the world, some RER stations were placed between two metro stations, so both could be connected with the RER. The most extreme case is that 6 metro and RER stations are connected underground (St-Augustin, St-Lazare, Haussmann-St-Lazare, Havre-Caumartin, Auber and Opéra).

The average metro station in Paris consists of a mezzanine at level -1 and two side platforms at level -2. The termini of the oldest lines used to have a loop (Place d'Italie M5, Étolie M6, Nation M6, Porte Dauphine M2). Some of these stations were actually doubled, since there was a station for the trains that terminate there and another one for the trains (and passengers) beginning their journey.

New York

The New York subway combines an extensive network of elevated trains (in Brooklyn and in the Bronx) with an underground train network that was built in the first half of the 20th century, especially in Manhattan. The subway links Manhattan with the other boroughs with tunnels or via the well known bridges, such as the Williamsburg Bridge or the Manhattan Bridge

A characteristic feature of this subway is the existence of local and express services in separate but parallel tracks, so a tunnel can have 4 tracks (2 per direction and 2 for each type of service). The express trains run in the central tracks and the local trains run in the side ones.

The elevated sections have stations placed above the streets and they can be accessed via staircases located in the sidewalks. Ticket halls are located at level +1, inside the viaduct, and platforms are at level +2, partially covered by shelters. The stations with express services tend to have central two platforms.

The underground lines run very close to the surface and they have plenty of piles of steel between the tracks and in the platforms. The stations that are served only by local services have side platforms at level -1, together with the ticket halls. Platforms are not linked via an underpass or an overpass. Express stations have two island platforms at level -2, allowing cross platform transfers between the local and express trains. In this kind of stations, mezzanines with the fare gates are located at level -1.

Prague

The three lines of the Prague metro form a radial network. All the lines cross at three selected stations in the city center. Almost the totality of the network is underground. The first line that was built (C) is the one running closer to the surface, especially at the city center and in the southern section. Lines A and B run much deeper.

The deep stations have island platforms at the deepest point of the station. The ticket hall, which is located beneath the street level, is connected with the platforms through escalators. A few stations even have two mezzanines, one at each end of the station.

Line C has not very deep stations at the southern part. They are composed of a island platform at level -1 and two ticket hall buildings located at ground level, each one at a different end of the platform.

At Můstek i Florenc, both metro lines run at a considerable depth, so both stations are linked through a rather short corridor, located at a level between both metro lines. Hoewever, Muzeum station has line C located close to the surface, whilst line A station is deep. Both lines are connected through a series of escalators.

Most of the metro stations have shops and stores in the ticket halls.

Rome

The Rome metro has few lines compared to the extent of the city. Until a few years ago, there were only two lines that intersected at Termini station, which is the central railway station as well. Because of it, Termini station is the one with the highest ridership of the city and most of the times it gets crowded. This station has one-way corridors for entering, exiting and even for transferring. A decade ago, the city had to build an extra set of escalators and corridors to decongest the existing link connecting lines A and B.

The other interchange station is San Giovanni. Line C opened in 2018 but the final passageway between both lines is not completed yet. Currently, passengers need to exit through the faregates and enter again.

The stations of the southern section of line B were opened in the 1950s and are very simple. The construction of the northeastern section of line B and the entire line A is much more recent and their stations were designed with one-way staircases and passageways.

Rotterdam

The Rotterdam metro has 5 different services that can be grouped into two lines. One of these services even arrives to the city of the Hague. The design of the stations is rather simple. For stations located underground, the layout consists of a mezzanine is located at level -1 and two side platforms at level -2. Elevated stations tend to have a island platform at an upper level and a mezzanine at the street level.

Blaak and Beurs have layouts were two lines cross, one over the other. The connection is provided via direct staircases linking both platforms.

São Paulo

The metropolis of São Paulo has a rapid transit network operated by three different companies. This is a relatively new metro (it was opened in 1968, despite some lines were converted from existing railways), with a layout and design thought to hold huge flows of passengers. Trains can be up to 200 m long.

Stations are very wide. Some of them, such as Sé or Luz (line 1) have the Barcelona solution, in order to ease the passenger flows.

Saragossa

Saragossa does not have metro but the commuter line C-1 has an urban section with three underground stations. This section was covered when the high speed rail line arrived to the city.

All the stations have a building at street level that hosts vending machines and the fare gates. Platforms are located at level -1, just under street level.

Miraflores station has a temporary access to a car parking, since the urbanisation of the street over the rail line has not been finished and the station building cannot be used. This station also has an underpass to reach the secondary platform.

Goya station has connection with the tramway, at Fernando el Católico station. The connection has to be performed by crossing two zebra crossings.

Valencia

The Valencia metro is actually the merge of different narrow gauge suburban railways that were connected via a tunnel crossing the city center. So this system is somehow the hybrid of a premetro and a rail, since in the city of Valencia is like a metro, but in the suburbs this works like a rail with lots of level crossings and single track sections.

The vast majority of underground stations have one or two mezzanines at level -1 and two side platforms at level -2. There are some stations with a different layout compared to the others, especially in lines 3 and 5: Bailén, Avinguda del Cid, Àngel Guimerà and Colón have island platforms. Alameda has four tracks and three platforms (2 for the Rafelbunyol line and 2 for the Marítim line).

Xàtiva station has a radically diferent layout, as the platforms are overlapped because there is the juntion of the line towards Bailén and Jesús just 20 m after the platform end (on the eastern side).

Warsaw

Line 1 has two types of stations: the ones located in the suburbs, having side platforms at level -1 and ticket halls at street level, and the ones located in the city centre, having a island platform at level -2 and a mezzanine at level -1.

The stations on line 2 are similar to the ones with a island platform on line 1, with the difference that the platforms are located a bit deeper.

There are two main transfer stations. Świętokrzyska is the crossing point of both metro lines and the transfer is quick. Half a kilometer to the south, there is the hub consisting of Centrum metro station, Śródmieście suburban rail station and the Central rail station. The latter two form a huge underground complex, combined with a shopping mall. The connection of Centrum and Śródmieście stations is done at street level.

Vienna

Part of the current metro network (U-Bahn) is inherited from a primitive urban rail network known as Stadtbahn that was steam-powered until the 1920s. Once the network was electrified, the rolling stock used was similar to the ones used for the tramways. Most of its network was elevated or ran at a street level, but without level crossings.

During the 60s, the municipal government decided to build a couple of tram tunnels. At the same time, they also planned a metro network consisting of a basic network, with parts of it coming both from the Stadtbahn (U4) and from the newly tram tunnels (part of current U2), asides from the construction of line U1. In the 1980s the second phase took place: line U3 was built and line U6 was integrated from the Stadtbahn.

The layout of the stations depends on the time they were built. The non-underground stations that were part of the Stadtbahn have side platforms and the access is made via the station buildings, which are in the Art Nouveau style. The stations that were part of the tram tunnel are located under street level and are quite simple: offset side platforms at level -1. The new stations built from the 1970s on typically have a island platform at the lower level and two mezzanines at the upper level, which can be either on street level or below, and is connected with the platforms via escalators or elevators. The depth of the latter stations is variable, but the ones located in the city center may be very deep.

All the transfer stations have been built after 1970 and their layout reflects the idea of having efficient links. Except for Praterstern, all stations have quick transfers.

Oslo

The current Oslo T-bane system originated from an old network of suburban trams that developed in the western suburbs of the city during the first half of the 20th century, and a modern metro system built from the 1960s onwards in the eastern part of the city. Both networks were progressively merged and unified between the 1970s and the 2010s.

The Oslo metro runs mostly elevated or on the surface, but there are also shallow underground sections. Surface stations usually have two side platforms. Access to the platforms is open, using an honor system, and access to the platforms is performed directly from street level through ramps. In some places, there is a Narvesen kiosk that serves as both a ticket reseller and a convenience store.

The underground stations are located either in the city center or in the northeastern suburbs. Most stations are situated at a shallow depth and have two side platforms at the deepest level. At the immediately higher level, there is a lobby that can be either at street level or underground. The connection between levels is made through ramps and staircases.

There are a few stations that are situated at considerable depth: Romsås, Ellingsrudåsen, Stortinget, Nydalen, and Vestli. Access to the first two is only possible through large-capacity elevators that connect the street to the concourse, in addition to a ramp of over 200 meters in length that also links the street to the concourse level.

Gothenburg

The Gothenburg tram has an underground station. Hammarkullen is located at a considerable depth, in a hilly suburb in the northeastern part of the city. The tracks pass through a dual tube tunnel. Trams run on the left only in this specific part, as the station has island platforms and the rolling stock only has doors on the right side. From the platform level, there is a flight of escalators and an inclined elevator that leads to the lobby, located at street level.

Hamburg

Hamburg has two rapid transit systems: the U-Bahn and the S-Bahn. The U-Bahn, which is the proper metro system, is one of the oldest in Europe. The first circular line was constructed combining elevated, at-grade and shallow underground sections. Subsequent extensions have also been built alternating these three typologies. However, the central section of U2 and the branch of U4 were constructed at a greater depth.

In general, the underground stations are quite shallow and have a island platform (side platforms in the original U3 stations). Some stations have an intermediate level serving as a lobby. On the other hand, the elevated stations have a street-level building (where the lobby is located) and a island platform or two side platforms at level +1.

The S-Bahn uses sections of the German railway network. The construction of the City S-Bahn (an underground line through the city center) started in the 1960s. Their stations have large island platforms located at level -2, generally with lobbies at level -1, standing at the ends of the platforms.

As for interchanges, some have been designed to facilitate cross-transfer connections (Barmbek for U3-U3 connections, Wandsbek-Gartenstadt, Berliner Tor, Altona, Hauptbahnhof between S-Bahn trains, Norderstedt Mitte), with parallel platforms (Ohlsdorf, Barmbek for U3-S1 connections, Hauptbahnhof Süd, Elbbrücken) or with direct transfers via a single flight of stairs (Schlump, Jungfernstieg).

There are other transfers that were poorly designed, such as the long passageway between Rathaus and Jungfernstieg, or the street-level transfer at Wandsbeker Chaussee, Dammtor/Stephansplatz, or Sternschanze.

Essen

Essen's Stadtbahn has two trunk lines. The one that runs through Rathaus station is a group of tram lines that run underground in the city center, with tram vehicles and low-level platforms. The lines that pass through Hirschlandplatz are light metros.

There is a variety of station typologies. The shallower stations usually have side platforms, while the trunk line stations of the light metro have island platforms, which are situated at a considerable depth.

Dortmund

Dortmund's Stadtbahn consists of three trunk lines located in the city center. The east-west lines are operated with low-floor trams, while the other two are operated with high-floor light metros. Most stations are located at a shallow depth. The station vestibules are either at street level or at an intermediate level between the street and the platform.

In Dortmund, there is also a monorail system (H-Bahn) that serves the Technical University of Dortmund (TU Dortmund). It consists of two lines. The track is single-track, but there are some stations with passing loops. All stations are elevated or at-grade.

Bochum's Stadtbahn consists of a north-south line, as well as several tram lines that run through underground sections in the city center. Most Stadtbahn stations have island platforms and vestibules located at an intermediate level between the street and the platforms. In some stations, the platforms are situated at a higher depth, such as Rathaus Nord and Hauptbahnhof.

Bochum

The Bochum Stadtbahn consists of a north-south line, as well as several tram lines that run through underground sections in the city center. Most Stadtbahn stations have island platforms and entrances located at an intermediate level between the street and the platforms. In some stations, the platforms are situated at a higher depth, such as Rathaus Nord and Hauptbahnhof.

Mülheim

The Stadtbahn stations in Mülheim are different. The stations that are close to the Ruhr have platforms at a considerable depth to allow the tunnels to pass underneath the river. The remaining stations have a typical configuration of any Stadtbahn network in Germany, with a vestibule at level -1 and platforms (either side or central) at level -2.

The Hauptbahnhof station is an intermodal hub that consist of elevated rail platforms, four underground Stadtbahn tracks with two island platforms and two underground bus platforms parallel to the Stadtbahn ones.

Duisburg

All Stadtbahn and underground tram stations in Duisburg have island platforms. These platforms are usually located at level -2, while level -1 is reserved for the lobbies.

There are two stations with a particular layout: Hauptbahnhof and König-Heinrich-Platz, which are the transferring points for the north-south and east-west lines. These stations have two parallel platforms, stacked on different levels (-2 and -3). Different combinations of escalators and staircases allow for transfers, access, and exit from the station.

Düsseldorf

Düsseldorf has two Stadtbahn main lines (north-south and northeast-southeast), as well as an underground tram main line. Both Stadtbahn lines share tunnels between the central station (Hauptbahnhof) and the city center (Heinrich-Heine-Allee), with tracks running parallel to each other. At Hauptbahnhof and Heinrich-Heine-Allee, the platforms serving the four tracks are located at the same level. However, at the intermediate stations, platforms are overimposed, being the northbound one on the upper level.

On the other hand, the underground tram stations have low side platforms at level -2 and a mezzanine at level -1.

Turin

Almost all metro stations in Turin follow a standard design consisting of two side platforms at level -3 and a lobby at level -1. The connection between the lobby and the platforms is made through escalators that go directly from the platforms to the lobby, elevators, or two flights of stairs.

Porta Nuova is the central rail station and has a different layout: the lobby is located at level -1 and platforms are at level -2, which can be reached by stairs or an elevator. There is a direct connection from the metro mezzanine to the railway station original hall, which is now part of a shopping center.

Porta Susa station has metro platforms at level -4, an intermediate level at -3, and an open hall located inside the large canopy that constits the railway station building. The railway station itself consists of three levels, with the eastern part of the station featuring a huge glass roof canopy measuring 380 meters long by 30 meters wide. Level -2 also contains the four rail platforms. On level -1 there are four passageways that connect the western accesses to the station and act as an intermediate level to connect crowds coming from the different platforms.

Lausanne

The Lausanne metro consists of a light metro line (m1) and an automated rubber-tired metro line (m2), which originated from a funicular that was later converted to rack railway operation.

The stations on the m1 are either locatred underground or at street level. Some stations have only one platform with direct access to the street, as the track is single-track. Stations with passing loops usually have two side platforms. The terminal station at Renens CFF is part of the Swiss Federal Railways station.

On the other hand, the stations on the m2 line are more varied. All stations have side platforms, except Sallaz. Some have platforms are located at street level, like Ouchy or Grancy. Others are very swallow and can be accessed via a staircase or ramp, such as Délices or CHUV.

Finally, some stations have a unique layout due to the topography of the old town, particularly the deep and narrow Flon Valley. Flon station is a main hub. It is located at Place de l'Europe. The m1 station is at the same level as the square, while the LEB (railway) and m2 stations are at level -2. From level -2, five elevators ascend to the height of the Grand Pont, located about twenty meters above.

Similarly, the Riponne station is situated in the Flon River Valley. The station is located at an intermediate level between the street following the valley and the Riponne Bridge. Four elevators (two per platform) connect the three levels.

Porto

The Porto metro is a newly constructed light metro. It has two trunk lines: one north-south and another east-west, with a section that follows the path of the former narrow-gauge lines that departed from Trindade, which now serves as a transfer station between the two trunk lines.

The surface stations have the typical design of a modern tram station, with shelters and pedestrian crossings at the ends of the platforms to switch platforms or exit the station.

The underground stations have side platforms at the deepest level, but there are differences in the layout of intermediate levels and the location of the booking hall.

Munich

The Munich U-Bahn is a metro system formed by 6 different lines, plus two that only operate during rush hours. The network has lots of spurs, but in the city center all those lines merge and form 3 trunk lines, in addition to an east-west trunk line of the S-Bahn, which, due to its frequency and performance, can be considered a metro, just like in Berlin and Hamburg.

Most stations have island platforms located at level -2 and a couple of lobbies located at level -1, just above the ends of the platforms. Any station has turnstiles: a honor system is used instead. In some specific stations the platforms may be located at a greater depth, which has required the installation of long escalators, like the ones in the central part of the U4 and U5.

One of the characteristics of the Munich metro is the presence of cross-platform transfers at many stations, with coordination on the arrivals and departures. Some examples include Scheidplatz, Innsbrucker Ring or Neuperlach Süd. Additionally, some other stations with terminating trains usually have three or four tracks, such as Hauptbahnhof (U1-U2), Münchner Freiheit, Olympiazentrum, Kolumbusplatz, Fröttmaning, or Implerstraße. Some of these stations have elevators that provide direct access between the platforms and the street.

The most centric S-Bahn stations use the Barcelona solution. At Hauptbahnhof and Karlsplatz, passengers board using the island platform and alight via the side platforms; while at Marienplatz, due to narrow streets, the two tracks are overlapped: passengers aight from the train using the right hand side in the direction of travel, and board through the opposite doors. Along with the two levels dedicated to the S-Bahn (-2 and -3), there is also the U-Bahn station located at level -4, whose platforms are separated by nearly a hundred meters since the streets above are narrow and the City Hall building is inbetween.

In other transfer stations, the line change is direct through a flight of stairs (Odeonsplatz, Hauptbahnhof, Sendlinger Tor) or through the vestibules in the case of most U-Bahn to S-Bahn transfers.

Nuremberg

The Nuremberg U-Bahn has three lines. Two of them, U2 and U3, share tracks in the central section and have automatic operation.

The station layout for most of the stations is quite simple. First of all, the ticketing policy is based in an honor system, so there aren't turnstiles in any station. The platforms are always located at the lowest level of the station, usually at level -1 or -2 (if the station has a mezzanine at level -1). In some cases, there is direct access from the street to the platform. All stations have elevators.

The two interchange stations between the U-Bahn lines are designed to provide quick transfers. At Hauptbahnhof, the U1 station is located one level below the U2 and U3 station, and only a short flight of stairs is needed to change. At Plärrer station, a cross-platform transfer is ensured in both directions, as the platforms of both lines are stacked.

Stuttgart

The Stuttgart Stadtbahn is quite complex, but its operation can be simplified into cross-valley lines and the valley lines. Outside the city center, tracks run on street level and most stations ressemble modern tramway stops. In the city center, stations are underground and have side platforms at level -2 and one or two lobbies at level -1.

The stations in the central section of the S-Bahn have a island platform at level -2 and lobbies placed at both ends of the platforms, at an intermediate level between the platform and the street.

Lille

The Lille metro consists of two VAL (light automated vehicle) lines. A VAL system is characterized by very narrow and short vehicles that operate at a high frequency in order to accommodate the demand. The narrow gauge is a direct consequence of minimizing tunnel construction costs.

Initially, the metro operated on an honor system, so the stations were designed to allow easy connections between streets and the plaforms. The subsequent installation of turnstiles means that some stations may only have them installed in certain accesses, while others may have a weird distribution turnstiles.

The main station of the network is Gare de Flandre, which is the central railway station and also a common station for both metro lines and tram lines, whose platforms are underground. This station provides a cross-platform transfer between the metro lines. Additionally, the transfer between the metro and the tram is also very fast. As a curiosity, the tram station has a platform exclusively for passenger alighting, since it is the last station.

The other interchange station between the two metro lines is Porte des Postes, where the platforms of the two lines intersect at different levels, but transfers are quick.

Palma

The Palma metro is a recent construction. The section closest to the city center was built by taking advantage of the underground section of the Palma-Inca line at the entrance to the city. Between the Intermodal Station at Plaça d'Espanya and Son Costa - Son Fortesa, the metro tracks run parallel to the aforementioned railway line.

The Estació Intermodal is the main transportation hub in Palma. There is an underground bus station located next to the underground railway and metro station. In fact, this hub is the starting point for all the interurban bus lines and rail lines originating from Palma.

All the underground section was built very shallow. In fact, the stations located on Gran Via Asima have the same design, with platforms and lobbies located at level -1 and an underground passage at level -2 equipped with escalators and elevators.

The Son Sardina station is located on the surface and provides an interchange with the Palma-Sóller line. The UIB station, on the other hand, has a street-level passenger building, although it does not host any facilities.

Brescia

The Brescia metro consists of a single line that opened in 2013. The rolling stock comprises Ansaldobreda’s automatic trains, also in operation on Milan metro lines 4 and 5. The line runs shallowly in the northern section, deeply in the city center, and on surface level and elevated through the eastern suburbs. An honor system is employed, eliminating the need for turnstiles.

Some of the deepest stations, such as Marconi, Ospedale, Stazione FS, Bresciadue, or Volta, follow a standard design with two side platforms at level -3. These platforms are connected to the mezzanine at level -2 via a staircase and two independent escalators. From the mezzanine, there is access to an intermediate level (-1) and a further flight of stairs leading to the street.

Shallow stations typically consist of two side platforms directly accessible from the street, while elevated stations feature an island platform.

Istanbul

Despite having 10 lines in operation, the Istanbul metro is quite modern. Except for lines 1 and 2, built in the 80s and 90s, the rest of the network was constructed in the 21st century. Extensions are underway in both the European and Asian parts of the city. The tram network complements the metro, which incorporates turnstiles at each stop. Additionally, the public transportation network includes four funiculars, three of which are entirely underground.

The metro lines exhibit significant differences in technical features, including train type, automation, track count, and electrification system. Construction methods for tunnels and stations vary from line to line, affecting station layouts. With the exception of line 1 which runs shallow or elevated, all lines run at considerable depths. Access and egress times are relatively high and some transfer layouts may result in long passageways or unnecessary multiple level changes. Moreover, transfers are not free, as passage through turnstiles is required.

All lines were constructed with dual-tube tunnels at depths ranging from 20 to 45 meters below ground level, except for line 1, which is shallower, and line 6, which was built with a single track and with passing loops at each station. Some stations are located as deep as 70 meters, only accessible via elevators in certain cases.

Malaga

The Malaga metro comprises two lines operated with a tramway fleet. Line 2 is entirely underground. Line 1 is mostly underground, but the western section of line 1 was built as a light metro with level crossings. The underground sections are shallow, with most stations featuring a lobby at level -1 and an island platform at level -2.

The common section is peculiar. Each line has its own tracks. The tunnel has two levels, with two tracks on each one. Between El Perchel and Guadalmedina stations, two tracks interchange their levels, in a section located within two curves. La Unión station on line 1 has also overlapped platforms. Atarazanas station only has a single platform.

Seville

The Seville metro consists of a single line that began construction in the 70s but was not opened until 2009. The rolling stock comprises tramway vehicles.

The central section, built in the 70s, features a dual-tube tunnel constructed using TBMs. Stations generally have a lobby at level -1 or -2, followed by an intermediate level and an island platform at the lowest level. Platform screen doors protect the tracks.

The western section, crossing the Guadalquivir river, includes elevated, surface, and underground sections. Ciudad Expo, the only station with both an island platform and a lobby at street level, stands out. Other stations have two side platforms, with the lobby located at either the upper or lower level, depending on the station's location.

The line runs shallowly between Nervión and Cocheras, with all stations featuring side platforms and a single lobby.

Palma

The Palma metro comprises a single line connecting the city center and the university campus in the north. The majority of the line is underground, with a surface-level section around Son Sardina. The segment between Estació Intermodal and Son Costa – Son Fortesa features quadruple tracks for metro and mainline traffic.

Estació Intermodal serves as a transportation hub with 10 platforms, a bus station at level -2, and a mezzanine at level -1. Jacint Verdaguer station has two island platforms at level -2 and a mezzanine at level -1. Son Costa – Son Fortesa station features two unconnected island platforms at level -1. The UIB station has two side platforms at level -1 and a ground-level hall. Son Sardina station is at ground level, with two side platforms connected by an underpass and linking to the Sóller Railway station. The remaining stations share a similar design, with side platforms at level -1, each directly accessible from the street, and an underpass connecting both platforms.

Naples

The Naples rail network comprises multiple lines operated by different agencies. The definition of what is part of the metro network varies.

Line 1, opened in 1993, connects the old city by the sea with the upper districts. The line forms a loop to climb the hill. Most stations are at great depths, except the section between Colli Aminei and Piscninola. Connections to platforms vary by station, but the booking halls are commonly located at level -1. Some feature a single flight of parallel escalators (Montedonzelli, Policlinico), high-capacity lifts (Duomo), or two or three flights of stairs. Stations between Colli Amiei and Museo have island platforms, while those in the old city have side platforms. Quattro Giornate station has overlapped platforms.

Line 2, owned by the Italian State, opened in 1925 with third rail electrification but was later converted to overhead lines. Montesanto and Cavour are the deepest stations, with a ground-level building comprising ticket office and turnstiles. Two flights of stairs and escalators connect to an intermediate level (-2), with two side platforms at level -3. Other stations, like Mergellina or Campi Flegei, are at ground level with grand station buildings. Piazza Garibaldi has two tracks and three platforms, with a recent layout change.

Line 6, closed since 2013, featured a narrow profile with trains only 2.20 meters wide.

The Arcobaleno line (Line 11) connects Piscinola with Aversa, built with cut-and-cover methods. The layouts resemble Milan metro lines 1 and 2 and Rome's southern section of line A. The Circumvesuviana and Circumflegrea lines are also part of Naples' rail network, with some underground stations.

Rennes

Rennes has two metro lines.

Line A is a VAL, an automatic light metro using technology developed by Siemens. The trains have a width of 2.08 m. Most of the line runs underground, with two elevated stations (La Poterie and Pontchaillou). The layout of the stations varies considerably, but all stations have side platforms on the lowest level. The lobbies are either located at street level or at level -1. Anatole France and Jacques Cartier are the deepest stations on this line. Initially, the stations had an honor system, but turnstiles were installed in 2020. Due to this reason, some lobbies might have a peculiar placement of the turnstiles.

Line B is a Neoval, an automatic line that uses more modern technology developed by Siemens. Trains operate in 2-car compositions, but stations allow for 3-car trains. The entire line runs underground except for the easternmost section, which is elevated. Platforms are located on the lowest level, normally at level -2 or -3. Mezzanines are located at level -1. Sainte-Anne is an interchange station located at the city center. Transfers, access, and egress are performed through a complex system of one-way corridors, stairs, and escalators.

Donostia-San Sebastian

Topo is a narrow-gauge rail line operated by Euskotren Trena, an agency owned by the Basque Government. This line runs through many tunnels, earning it the nickname "Topo," which means “mole” in Spanish. The line underwent a major renovation in the last 10 years, and a variant is being built both in the city center of San Sebastian and in the neighboring town of Pasaia. As a consequence, the current main station of Amara will be closed and dismantled.

The layout of the stations differs. Lugaritz, Anoeta, and Herrera have a station building at ground level and two side platforms at level -1. Loiola and Pasaia stations are elevated. Intxaurrondo and Altza stations are located deep underground and have layouts and aesthetics similar to those of the Bilbao metro, once designed by Norman Foster.

Sofia

The Sofia metro consists of 4 different services that operate on 2 physical lines. Despite having rolling stock manufactured by a Russian company, the aesthetics and layouts differ from the Soviet-influenced metros of eastern European countries. Generally speaking, the average station has lobbies located at levels -1 and the platforms at level -2. Most stations have side platforms, but the oldest ones, located in the central part of lines 1 and 4, have side platforms. Stations in the common section of lines 1 and 4 have low-cost platform screen doors.

All stations on line 3 have side platforms, normally located at level -2. Mezzanines are commonly located at level -1. The connection between platforms and the mezzanine is performed by multiple staircases or elevators. Most of the accesses to the stations are equipped with elevators.

Toulouse

The Toulouse metro is formed by two lines that form a cross-shaped network. Both lines use VAL technology and are automated. The layout of line A stations varies. In the city center, the line runs through a dual-tube tunnel at a great depth to cross the Garonne river. Long escalators reach the platforms at Capitole and Esquirol. Stations located outside the city center tend to have a lobby at level -1 and two side platforms at level -2 or -3. The western terminus at Basso Cambo is elevated.

Most of the line B stations have a similar layout consisting of a lobby at level -1, an intermediate level used for entering passengers at level -2, and two side platforms at level -3. Passengers egressing the station can use escalators that connect directly the platforms with the lobbies. Jean Jaurès is the main hub on the network. The station was designed to have one-way passages and escalators. The line B station uses the Barcelona solution, boarding through the island platform. Passengers need to pass through turnstiles to change from one line to the other. These turnstiles are used only for statistical purposes and to manage flows, as the tariff system guarantees free transfers.

Zurich

In 1962, the citizens of Zurich rejected in a referendum the conversion of tram lines in the city center into a premetro. In 1973, the citizens rejected again the construction of a metro network. However, a short section of the tunnels was already being built to conduct rolling stock tests. In 1978, the citizens approved integrating the existing tunnel into the tram network, which was completed in 1986. These stations were built at a considerable depth, as they are located in a hill between the valleys of the Limmat and the Glatt rivers. All stations have island platforms. Since trams in Zurich only have doors on the right side, they run on the left side of the tunnel. All the stations have multiple accesses, some reachable only via elevators, others via a long flight of stairs and escalators, which in some cases have the lower side in a level located even below the platform level.