Milan Part 2: Tram City to Metropolitana City

The post-war tramway shrinks but holds

The war years brought severe destruction upon the city, as tracks and thousands of tram cars were destroyed in the bombings. When the city was finally liberated the 25^th of April 1945, it took several years before a complete restoration of the tramway service.

However, unlike many other European cities, Milan’s urban tramway network was never abandoned, even if it suffered from neglect and disinvestment in favour of the Metro and the trolleybus/bus network. A major network rearrangement in the 1970s brought the closure of several sections, mainly in the city centre, where lines’ layout was simplified and many mixed-traffic alignments in narrow streets were abandoned. Although, despite shrinking within the inner city in favour of the metro and a simpler layout, the tramway was extended to the new, mainly working-class neighbourhoods growing far out from the former city limits in the south extensions. The real victim of the postwar years was the interurban tramway network. By the 1970s, only two lines had remained of what was previously an extensive network covering the whole region, as we covered in Part 1.

the Metropolitana becomes a reality

With the war finally over, the real protagonist of the post-war boom emerged as the Metropolitana the underground rail metro. After years of gestation and increasingly refined projects, the growing congestion and the quickly expanding economy of the 1950s accelerated the decision to build a four line initial Metro network, with priority given to the Red and Green lines. The project was almost completely financed by the Municipality through the issuance of dedicated bonds, as the government considered local transit a municipal “problem” and was busy developing the national motorway network. A municipally owned concessionaire, Metropolitana Milanese S.P.A., was created in 1955 to design, construct, and operate of the metro network. Works finally began in 1957 on the first line, la Rossa-M1 (Red). It connected the north-eastern municipality of Sesto San Giovanni, an important industrial centre dubbed the ‘Stalingrad of Italy’ as it was a stronghold of the Communist party, to the city centre, passing right next to the Duomo and the Galleria Vittorio Emanuele. Then it continued west under the walls of the Sforzesco Castle, separated into two branches, one of them connecting to the growing, mostly social housing district known as Q.T. 8.

The first line was completely built in cut and cover, using a new tunnel construction technique dubbed the ‘Milan method’. Retaining walls are directly dug in the soil using a ‘slurry wall’, a mixture of clay and bentonite that prevent the trench retaining wall from collapse before concrete is poured in. Even though this technique proved very fast and cheap, it caused incredible disruption of the streets, and its use in the city centre for further lines was limited by the little number of thoroughfares large and straight enough for surface digging. Many more construction pictures can be found here.

In the early 1960s works for la Verde-M2, (Green), started as well, although using mainly deeper New Austrian Tunnelling Method (NATM) techniques to reduce the kind of surface disruption experienced with the Red line. also because the alignment was along narrower streets or under densely built city centre blocks and, again, the Sforzesco castle. The NATM involved digging the tunnel trench under the street, then providing a temporary road surface while tunnel construction is completed underneath.

The first 12.6 km stretch of the Red between Sesto-Marelli and Lotto line finally opened the 1^st November 1964. More sections opened in the following years, with the first 6.7 km of the green line opening in 1969. Lines M1 (Red) and M2 (Green) kept growing throughout the 1970s and 1980s, reaching further out the expanding peripheries of the city. Notably, the Green line finally incorporated in 1972 the Linee celeri dell’Adda, a completely segregated double track line opened in 1968. This originated from the reconstruction to LRT/metro standard of part of the outer section of the Milan-Vaprio interurban tramway, one of the first interurbans to be opened in the 1870s. Supposed to reach further out east and north-east to connect the densely populated towns along the Martesana Canal connecting Milan to the Adda river, the line was only eventually extended only a few kilometres beyond Gorgonzola (yes, the town of the renowned cheese) in the 1980s. A before/after video of the Linee celeri dell’Adda is here.

The Linee celeri dell’Adda was not the only project intended to replace the aging and increasingly traffic clogged interurbans, by integrating it into the metro network to increase regional accessibility. The necessity to keep a fast and reliable rail connection to Milan’s hinterland, characterized by a dense constellation of closely spaced towns spreading in the west-north-east area stretching to the Lakes and the Alpine Piedmont, had already prompted in the 1930s several proposals for a region-wide metro network complementing the rail service offered by FS and FNM.

However, the only other interurban project that came close to realisation was the Linee celeri della Brianza, the twin project of the Adda’s fast lines. It was supposed to convert first to fully segregated tramway then to full metro standard the interurbans connecting Milan to the north, serving areas not directly connected by mainline rail. The lines, mostly above ground, were intended to terminate at Garibaldi FS M2 metro station with cross-platform exchange and potentially full through operation with the Green line. For that reason, Garibaldi FS station was built with four tracks and two island platforms. Unfortunately, construction was never started due to lack of funding and commitment from the central government. Garibaldi FS station’s extra two tracks are now used for trains storage.

Construction of the third line envisioned in the original plan, la Gialla – M3 (Yellow) started in the 1980s, with the first section opening in the 1990s and slowly being extended south-east and north-west. In the city centre, the line crosses near or under several delicate monuments and along extremely narrow streets where the line has been built in double-stacked tunnels to allow for more compact stations.

Style is not an option in Italy

On the design side, Milan’s metro continued the city’s architectural tradition with its sober and functional modernist station design by Franco Albini, Franca Helg, and Bob Noorda. The network was awarded the prestigious Compassod’Oro (Golden Compass) for industrial design for its use of materials, colour-coded finishing for the different lines and carefully designed signage combined in a sort of plain and functional architecture, reflecting the reputation of the Milanese being practical people and somehow diverging from the more flamboyant brutalism of other post-war metro systems, like Montréal’s.

The rail comeback to the city: the ‘Passante’ city rail link

Finally, the fourth line of the original 1950s Metropolitana plan was built during the 1980s and 1990s, but not as a Metro, but as a cross-city rail tunnel for regional rail service – the Passante Ferroviario. In the post-war years most of the attention was concentrated in the development of the inner-city rail network, notably the Metro. The only remarkable exception is the construction of the new Porta Garibaldi terminal and the completion of a new short underground rail tunnel, dubbed the ‘Passantino’, connecting the station to the rail ring to enable through service. This station was part of a lager scheme elaborated in 1953 to create a Central Business District (Centro Direzionale) in the area stretching from the Stazione Centrale, where new skyscrapers were already springing up and the new Porta Garibaldi station (notably the Pirelli tower, for a short while the tallest building in Europe), taking advantage of the large areas liberated by the demolition of the ‘Varesine’ passenger terminal station and of what remained of the oldest city freight yard.

Porta Garibaldi terminal was poised to became the main city station for commuters. The first section of M1 opened in 1964 and is depicted in yellow. The ‘Passantino’ dashed line represents underground tunnel.

But the real comeback of mainline rail into the city’s core happened many years later, with the construction of the Passante Ferroviario, a cross-city tunnel for through-running regional trains. Talks about a cross-city rail link for local trains started as early as the 1960s, when a number of factors started to congeal:

• the urban growth started to shift toward the vast hinterland and the increase in car traffic entering the city
• made more urgent to provide a faster rail connection to the wider region,
• avoiding to reverse trains at the stub-end stations of Cadorna, Centrale, Porta Garibaldi, and Porta Genova.

More importantly, the Passante Ferroviario cross-city tunnel was only the tangible part of a vision for a comprehensive regional rail service modelled on the Paris Reseau Express Metropolitain (RER), but even more on Germany’s S-Bahns, notably Munich, envisioned in the 1982 regional mobility plan.The cross-city link was intended as the central spine of a far-reaching suburban service reaching some 30-50 km out, with lines running every 30 minutes from 5 am to 12 pm, every day of the year with identical schedules. Combined lines would give a 10-15 minute headway on busier branches and 3 minutes on the central section along the Passante. In addition, a regional service with a 30-60 minute headway would terminate in stub-end main terminals, skipping inner stations and providing an express service for commuters coming from further out, in a 30-80 km radius. The final piece of the puzzle was the Regio-Express service, running hourly or bi-hourly, providing a fast connection between Milan and the other major cities and towns of the Region.

In Milan’s initial plan in the 1960s and 1970s, two Passanti were envisioned: first the east-west line following mostly the alignment of the original railway ring from Porta Garibaldi to Porta Vittoria. Then a north-south line connecting Porta Genova station to Bovisa and the line to Turin.

Surprisingly, none of the two tunnels envisioned in the early plans would have been connected to the main station, Milano Centrale, unlike in the German examples of Munich, Stuttgart, and Frankfurt that were Milan’s inspiration. This is one of the main flaws of the existing Milan’s Passante, as it doesn’t allows a seamless connection between suburban trains and long distance ones that are mainly concentrated at Milano Centrale.

Priority was given to the east-west tunnel, whose construction started in the second half of the 1980s, mainly with regional and municipal funds. Unfortunately, the project was slowed down by the lack of resources from the central government, and the big corruption scandals of the beginning of the 1990s that blocked many major public works throughout the decade. The core of this cross-city line is a 7.8 km tunnel with 6 underground stations, with 250m long high-level (55cm) platforms. The tunnel has two access points from the west (from both the FS Milan-Turin line and the FNM Saronno and Erbalines routes), and two from the east connecting to the ring line and the lines to Venezia, Bologna, and Genoa.

The construction of the underground stations, especially in the city’s core where the Green, Yellow, and Red Metro lines interconnect, has proven quite challenging because of surrounding buildings’ foundations and the waterlogged ground. In particular, Porta Venezia was built partly under the Red line station in a very wet and unstable alluvial soil using a new technique called ‘cellular arches’. The 29-wide vault is formed by aligned pre-fabricated concrete cylinders of 1.5m diametre pushed horizontally into the soil from a construction shaft to form the upper part of the vault. The remainder of the vault side is realized through micro-tunnelling and arches strengthening the structure. The result is a wide single cavern with a rhythmic vault and a suspended mezzanine covering the whole station.

Four more above ground stations were built or modernised to provide dedicated space for the suburban trains. As the Passante opened in stages from 1997 to 2003, an initial phase of the ‘S-lines’ suburban system envisioned in the 1982 plan. the whole ‘S’ system started operating with only 5 lines on 30 minute frequencies in 2004, giving a combined 6 minute/10 train per hour (tph) frequency in the shared core section. And there is only partial through-running, pending the completion of the western access and other capacity improvement around the network:

The whole S-lines network started slowly, but has seen a progressive and continuous implementation of the service with many major expansions in 2008-9, in 2012, and in 2015. Although the first years the suburban service were criticised for being underutilised, usage has grown steadily as service was stepped up, a clearer fare integration policy was established, new more performing trainsets were purchased, and more infrastructure improvements were completed. As a result, the Passante, which had only a few thousands riders in the first years, rose to 70,000 riders/day in 2014, 10 years after the opening, and was used by 184,000 users/day in 2018, with 6 interlined lines giving a combined 5 minute/12 tph frequency. In the same period, the whole Lombardy’s regional rail network doubled its ridership, from 400,000 users/day in the early 2000s to more than 800,000 in 2019.

But the potential of this infrastructure is much larger still, as Munich’s 40 tph, 800,000 daily user cross-city tunnel shows. Unfortunately, Milan’s lack of dedicated metro-style rolling stock (open gangways, wide doors, high acceleration), an old signalling system, and driver plus conductor train operation increases station dwell times and limits average speed. Thus the overall performance of an otherwise state-of-the-art infrastructure is hindered. In effect, Italian state railways has been notoriously slow in adopting modern practices for Regional Express Rail, preferring to stick to a more traditional way to operate local trains ill-suited for closely spaced stop patterns.

For that reason, the new 2010s city mobility plan pushes clearly in the direction of a German-style S-Bahn style of operation, in order to increase the number of trains to at least 16 tph giving a 3 min 45 sec headway, while raising the average speed, with changes in operating patterns, purchase of improved rolling stock, new signalling, and some new infrastructures.

tramway COMEBACK, & small metros: M4-M5

There was a general slowdown of public works in Italy in the 1990s. The corruption scandals of the late 1980s, the early 1990s recession, and the effort to curb the public debt before entering the Euro area resulted in little new rail infrastructure being built. All of Milan’s efforts were put toward completing the La Gialla M3 Metro and the Passante, as both were largely financed by the municipality. Building a full new heavy rail subway was considered too expensive, so the city put more emphasis in speeding up existing lines and building modern tramways in completely segregated right of ways. This resulted in the opening in the early 2000s of the three Metrotranvie:

• Interperiferica Nord, a tangential line cutting east-west in the northern suburbs connecting several peripheral new development areas, notably the Bicocca brownfield redevelopment;
• Metrotranvia Sud, connecting the city centre with the southern periphery; and
• Metrotranvia Nord, connecting the Sforzesco Castle with Cinisello Balsamo in the northern hinterland.

These three lines were the first to operate completely low floor, bi-directional, 32m-long articulated trams.

But thanks to the advent of small scale light automatic metros and new public money available for large infrastructure projects from the 2000s, Milan started again planning for two new metro line: la Blu M4 (Blue) and la Lilla M5 (Purple). Both lines use short 50m-long and 2.65m wide automatic trains on steel wheels manufactured by AnsaldoBreda (now Hitachi Rail Italy), the same used in Copenhagen and Brescia metros. This broke with the previous standard of wider 105m-long trains on older lines.

The first line to be built was M5. It was initially planned as two lines (M5-M6), both terminating on the opposite side and at the same level of the existing M2 1960s Garibaldi FS station. From a transport planning perspective, this forced travellers to transfer, but was considered the most feasible option because of the underground complexity of several road, metro, and rail tunnels in the area. Plus the necessity to coordinate with the then under construction UniCredit tower.

Fortunately, the more rational decision to join the two lines in a single M5 was made. This brought to a complete redesign of the whole section with a single, deeper station for M5 in a slightly different location. But that was an engineering challenge itself. The new alignment crosses seven underground obstacles in less than 400m. starting from the north, the M5 tunnel passes:

• over the twin-tubes of M2 (Green),
• under the Passantino rail tunnel,
• over a planned cross-city deep twin-tube highway (fortunately never constructed),
• under a concrete box road tunnel, part of the whole Garibaldi area’s masterplan,
• under 3 stories of underground parking,
• over the Passante rail tunnel, and finally
• under the M2 (Green) station.

All that while transitioning from the single-bore of the north section to the twin-bore of the eastern one. To make things a little more complicated, a M5-M2 track connection was added in the same location, as it is necessary to allow M5 trains to reach the M2 maintenance centre, since M5 will have its own only after a currently planned extension is built in the mid 2020s. The planimetric and altimetric profiles of the line are more like a rollercoaster than a metro line, and the proximity of existing structures made the use of a TBM impossible. All complicated by Milan’s alluvial soil made of clay and sand, with a high and variable water table.

Several different excavation techniques were used to complete this 400m segment: ‘Milan method’ cut and cover, localized micro-mining with soil consolidation through jet grouting and freezing, and sub-foundation with micro-piles under existing station boxes. With the construction of the northern section started in 2007, the whole 12.9km, 19 stations line was opened in stages between 2013 and 2015.

The fifth line is la Blu M4, whose construction started partially in 2015. It’s another fully automated light metro. The main difference is that it has a more central alignment within the Spanish Bastions, along the Cerchiadei Navigli, the inner ring of now covered canals and 12^th century walls and moat. Due to the lack of space to build station boxes, the tunnels of the 4.5 km central section have a large diametre of 8.5m that can accommodate both trains and platforms. To avoid interference with building foundation and other metro tunnels, the line is also 20-25 m deep. Even so, the central alignment had to be refined several times to weave away from potential archaeological findings, old building foundations, underground canals, etc.

As a result, M4 Blue intersects but does not interchange with the M3 Yellow line, as it was deemed not cost-effective to build an underground pedestrian tunnel avoiding all those obstacles. Nevertheless, the line is today in advanced construction: tunnelling is finished, and the western section will open in 2021, with the remainder opening in stages by 2023. With this new line, the network will reach 112 km and an estimated 1.55 million users a day.

The growing network is improving mode share

The investment in transit of the last two decades is already bearing fruit, spurring a constant increase in transit ridership, around 20% in just the 2003-2013 decade. The metro alone carries some 1.35 million daily passengers, and the surface network some 970,000 within the city and 1.1M in the whole metropolitan area. This comprises 385,000 daily users for the tramway, 136,000 for the trolleybus, and 450,000 for the bus network in 2017. The regional rail network reached 800,000 daily users in 2018, a 23% increase in only the last 10 years.

From 2003 to 2013, the transit share of trips starting and finishing within the city rose from 51% to 57%, while it rose, but slightly less, for trips entering the city from outside, from 34% to 37%. Car ownership, which had peaked in the early 1990s at more than 730 cars per 1000 inhabitants, has since consistently shrunk to 507 per 1000 inhabitants in 2019. The introduction of a first road pricing system in 2008 (Ecopass) and a further one in 2012 (Area C), combined with the previously existing Limited Traffic Areas (ZTLs) in the core of the city, are curbing both car usage and ownership. Yet, Milan is far from being the perfect transit city, despite the efforts to catch up in the last decades. And there is a lot of room for increasing both transit and bike usage in the future.

Planning for Milan’s public transport future

The New Sustainable Mobility Plan (PUMS – Piano Urbano per la Mobilità Sostenibile) calls for a further development of the city’s rail network. For the first time in decades, the tramway is getting a major boost, with traffic lights priority being implemented along several routes and the progressive transformation of some high traffic lines in faster metrotranvia light rail lines, along with further extensions in the periphery.

After many years of delay, the interurban tramway to Desio-Seregno, closed in 2011, will be replaced with a metrotranvia line. The other surviving interurban to Limbiate is also slated to be similarly upgraded.

A major modernisation of the tram fleet is underway: the first group of 80 25m-long cars ordered from Stadler will hit the street in 2021, replacing the ageing Jumbotrams from the 1960-70s. But no worries, the iconic ventotto, now almost a century old, will not be decommissioned and will continue to operate on many low traffic lines, as they are cherished by the Milanese and are an integral part of the city’s landscape.

And the Metro is continuing to expand – several extensions for M2 and M1 are under construction or financed. A major 12km northern extension of M5 to Monza is fully financed and construction will start in 2021. A sixth metro line is envisioned in the mobility plan, to start construction at the end of the decade, although early planning has already started.

The main rail project of the next decade is the transformation of the half rail ring to a surface circle line, combining existing and new S services to achieve a 5-7 minute (9-12tph) headway.

The completion of the Milan-Venice high speed line in the second half of the 2020s will likely put additional heavy pressure on the existing dedicated long-distance tracks around the city, with all the trains terminating and reversing at Milano Centrale. This station today moves more than 750 trains a day on its 24 tracks, up 40% from 2011, and is now approaching capacity. Over the longer term, a second Passante will come back to the design phase, as well as a cross-city high speed rail tunnel, as the outstanding success of the FS high speed service opened in 2009 has brought to a rapid saturation of the rail ring with both local and long distance trains.

The future

Milan, like most large cities, has been incessantly building and rebuilding its transport infrastructure to make its future-proof and adapt it to the growing mobility needs of what is today an urban area of 4.4 million, in a wider region of 10 million. It must, and hopefully will, continue to expand and modernize its rail network in the next years, to increase the livability and curb car usage and emissions. Much work has been done, but there is much work still ahead.

This guest post is from Marco Chitti, PhD candidate in Urban Planning at l’Université de Montréal.

Uncredited photos, and those by Giorgio Stagni, drawings and articles are licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.