The Breadth and Structure of Milan's Bus Network

Milan's bus system is one of the most extensive components of the city's public transportation network, offering crucial connections across all nine municipi and into surrounding municipalities. Operated by Azienda Trasporti Milanesi (ATM), the bus network supplements the metro, tram, and suburban rail systems, reaching areas not directly served by rail infrastructure. As of 2025, over 80 urban bus routes operate throughout the metropolitan area, serving millions of passengers annually.

The network is designed to connect residential neighborhoods, business districts, hospitals, schools, and transit hubs. It includes high-frequency lines, local circulators, radial routes that link outer districts to the center, and tangential lines that enable cross-city travel without passing through downtown. While some lines are longer and pass through multiple districts, others are short but essential for bridging last-mile gaps. These varied roles make buses indispensable in maintaining full geographic coverage of Milan's urban environment.

Key Bus Lines and Areas of Coverage

Several Milanese bus lines stand out for their strategic importance. Line 56, for instance, runs from the Loreto area northeast toward Q.re Adriano, offering connections to M1 and M2 metro lines and servicing both residential and commercial zones. Line 60 runs from San Babila in the city center to Zara in the north, serving high-traffic corridors used by both commuters and shoppers. Line 90 and 91—although technically trolleybus lines—are functionally similar to surface buses and form a ring route around the city.

Suburban routes like Line 701 and 702 extend beyond Milan's borders, linking towns such as Rozzano, Assago, and Pieve Emanuele to the urban core. In peripheral districts like Baggio, Affori, and Ponte Lambro, buses provide essential lifelines, especially for populations less served by metro or train. Many routes are designed to interface with major railway stations such as Centrale, Garibaldi, and Cadorna, helping passengers transition between long-distance and local travel.

Frequency, Operations, and Service Hours

Bus service in Milan typically operates from around 5:30 a.m. to 1:00 a.m., though some lines—particularly those connecting nightlife or intermodal hubs—operate later or run 24 hours. Line N services (notturni) specifically cover nighttime routes and provide vital access for workers, hospital staff, and late-evening commuters. Frequencies vary by line, but high-demand routes during rush hours can operate as frequently as every 7–10 minutes.

Buses are tracked in real-time via the ATM Milano app, allowing riders to check estimated arrival times and plan transfers more efficiently. Many lines now feature new-generation buses with digital displays, low-floor boarding, and space for wheelchairs or strollers. Vehicle upgrades and route optimizations are ongoing, with ATM evaluating ridership data and traffic conditions to refine service schedules and improve reliability.

Environmental Goals and Bus Fleet Modernization

Milan's bus system is at the forefront of the city's transition toward low-emission urban mobility. In recent years, ATM has invested heavily in electric and hybrid buses, gradually phasing out older diesel models. The city aims to convert the entire fleet to electric or hydrogen-powered buses by 2030, with over 200 fully electric units already in operation as of 2025. These vehicles reduce noise pollution and greenhouse gas emissions, supporting the city's climate and air quality objectives.

The transition to greener buses includes not just new vehicles but also infrastructure upgrades such as charging stations at key depots and transit nodes. Routes with frequent service and high passenger volumes are prioritized for electric fleet deployment. Additionally, ATM participates in European Union sustainable transport initiatives, integrating Milan's efforts into broader continental goals for decarbonization and energy efficiency in public transportation.

Accessibility and Multimodal Integration

ATM ensures that Milan's bus system is fully integrated with other modes of public transportation, offering seamless transfers to metro, tram, and suburban rail services. Unified ticketing allows riders to use the same fare card across all modes, and signage at major stops displays both bus and connecting transit options. Strategic interchanges like Lotto, Lambrate, and Romolo enable easy movement between surface and underground transport options.

Accessibility features are standard on newer buses, including retractable ramps, audio announcements, and designated seating for elderly and disabled passengers. Milan's urban planning has prioritized the redesign of bus stops to include shelter, lighting, and information displays. These enhancements support comfort and accessibility for all users and align with ATM's broader commitment to equitable, barrier-free transit infrastructure.

Challenges and Future Outlook

Despite its strengths, Milan's bus network faces challenges related to traffic congestion, construction detours, and occasional service disruptions. ATM continues to invest in dedicated bus lanes and signal prioritization systems to improve punctuality and service speed, particularly in areas with frequent bottlenecks. Public feedback is also regularly solicited to refine routing and identify underserved areas in need of additional service coverage.

Looking forward, the bus system will remain a critical pillar of Milan's mobility framework. Continued investments in green technology, digital service tools, and route efficiency will ensure that buses not only complement other transit methods but also stand on their own as a reliable and sustainable transport option. With the city's population and infrastructure evolving, the adaptability and reach of buses will be key to maintaining high-quality, inclusive urban mobility.