1. Introduction: Carbon Neutrality Imperative and the Strategic Framework of the Transport System

The City of Helsinki’s strategic goal to achieve carbon neutrality by 2030 forms the bedrock upon which all future transport solutions are built. This goal, which has been accelerated from the previous target of 2035, places exceptionally high demands on the coordination of urban structure and mobility services. Transport is the most challenging of Helsinki’s emission sectors; it constitutes over 20 percent of the city’s direct greenhouse gas emissions, and unlike energy production where emissions have fallen, emission reductions in transport have progressed slower than the target trajectory.

This report analyzes in depth the current state and future potential of Helsinki’s public transport, answering the question: How do theoretical innovations transform into practical solutions in an ecological city? The analysis spans the evolution of current modes of transport—metro, trams, light rail, buses, and ferries—to completely new technologies still looming on the horizon. The report also examines why certain theoretically attractive solutions, such as cable cars or Personal Rapid Transit (PRT), have faced insurmountable obstacles in practical implementation within the Helsinki context.

1.1 Strategic Goal: -60% and Carbon Neutrality

The Helsinki City Strategy 2017–2021 and its updates have locked in the goal of reducing greenhouse gas emissions by 60 percent by 2030 from 1990 levels, aiming for full carbon neutrality by 2035. This requires a radical shift away from internal combustion engine technology and private motoring. Helsinki Region Transport (HSL) has outlined in its strategy for 2025–2030 the goal of being a “leading actor and partner” that not only operates transport but enables the vitality and sustainability of the entire region.

On a practical level, this means that public transport must be a more attractive option than private motoring—not just in terms of price, but also in terms of smoothness, speed, and experience. In this equation, digitalization, automation, and electrification are key drivers of change.

1.2 Symbiosis of Urban Structure and Transport

The ecological Helsinki of the future is not just a technological project, but a choice in urban planning. New master plans and land use plans guide growth to rail transport hubs. “Rail City” is a term that describes the transition from a bus-based decentralized structure to a dense city relying on rails. This is concretely visible in projects like the Vantaa Light Rail and the Viikki-Malmi Light Rail, where the rail network serves as the backbone of urban development.

Target Year	Emission Target (vs. 1990)	Role of Transport
2030	-60 %	Electrification of public transport, expansion of rail transport, promotion of walking and cycling.
2035	Carbon Neutrality	Possible ban or restriction on internal combustion passenger cars, fully electric HSL transport.

2. Renaissance of the Trunk Network: Evolution of Rail Transport

Rail transport represents the pinnacle of energy efficiency in an urban environment. The rolling resistance of a steel wheel on a steel rail is a fraction of that of a rubber tire on asphalt, and electric traction has been the standard for rail transport for decades. In the ecological Helsinki of the future, the role of rail transport will grow even further, but it will change its form: the metro will be automated, and tramways will expand into regional light railways.

2.1 Metro: The Dilemma of Automation and Capacity

The Helsinki Metro is the backbone of the system, carrying the largest masses of passengers between east and west. The completion of the West Metro has extended the line, but at the same time, it has highlighted capacity problems.

2.1.1 Theory: Why Is Automation Necessary?

Theoretically, metro automation (GoA4 level, i.e., a system operating entirely without a driver) is the only way to increase capacity without billion-euro tunnel investments.

• Tightening headways: Current manual driving allows for a minimum headway of about 2.5 minutes. An automated system could shorten this to 90 seconds, which would increase the line’s capacity by tens of percents.
• Energy efficiency: Computer-controlled driving optimizes acceleration and braking (eco-driving), saving energy and reducing wear.
• Flexibility: An automated system can react to demand spikes by bringing additional trains into service faster than human drivers can be called to the site.

2.1.2 Practice: Challenges of Implementation

Helsinki’s metro automation project has been a long and rocky road. The project has been prepared and suspended several times due to technical and financial risks. The practical challenge lies in reconciling the old system (Siemens/Valmet rolling stock) with new technology while traffic is running.

• Current Situation 2024–2025: HSL and Metropolitan Area Transport Ltd are currently focusing on basic renovations of the network. The operating plans for 2024 and 2025 are full of interruptions: The stations of Rautatientori, Mellunmäki, Kontula, and Myllypuro are closed due to renovations. This is a necessary step before a decision on large-scale automation can be made again.
• Future Extensions: The vision still holds the idea of a “Metro 2” line or extending the eastern metro to Östersundom, but these depend on land use solutions that have been delayed.

2.2 Light Rails: The Backbone of City Boulevards and Cross-Town Traffic

The most significant change on the Helsinki transport map in the 2020s and 2030s is the emergence of a light rail network. This represents a paradigmatic shift where the tram is no longer just a slow vehicle of the inner city, but a regional, fast means of connection.

2.2.1 Raide-Jokeri (Line 15) and Its Legacy

Raide-Jokeri has served as a “proof of concept” project. It replaced the congested bus line 550 and demonstrated that a rail connection significantly increases passenger numbers (“rail factor”).

2.2.2 Vantaa Light Rail: Driver of Growth

The Vantaa Light Rail is an approved project that binds Vantaa more tightly to the regional rail network.

• Route: Mellunmäki (Metro) – Hakunila – Tikkurila (Train) – Aviapolis – Airport. Length is 19.3 km.
• Strategic Importance: The project is not just a transport project, but an urban development project. It enables dense residential construction along the route, reducing Vantaa’s dependence on private cars. Estimated completion is in 2029.

2.2.3 Viikki–Malmi Light Rail (Viima)

This project is an example of how public transport is planned before settlement, which is the golden rule of ecological urban planning.

• Context: Transforming the Malmi Airport area into a residential area for 86,000 people. Without efficient public transport, the area would choke on cars.
• Schedule: The general plan was approved by the Helsinki City Council in April 2025. Construction could begin in 2028 and operations in the early 2030s.

2.2.4 Crown Bridges: Why Did the Tram Win Over the Cable Car?

The Crown Bridges project connecting Laajasalo and the city center is an interesting case study of the “theory vs. practice” setup.

• Theoretical Option (Cable Car): A cable car (gondola lift) was ideated and studied between Laajasalo and the center. Theoretically, it would have been cheaper to build, quiet, and visually futuristic.
• Practical Realities (Grounds for Rejection):
  1. Weather Conditions: Helsinki’s maritime location is windy. Service interruptions due to storms would have been too common for a reliable trunk connection.
  2. Capacity: Tram capacity is superior during rush hours. One tram carries hundreds of passengers, whereas the capacity of gondola lifts is more limited.
  3. Networking: The cable car would have remained an “island,” requiring a transfer at both ends. The tram integrates directly into the Hakaniemi and Railway Station network without a transfer.
• Implementation: The Crown Bridges tramway will be completed in 2027. Before that, in 2025–2026, massive construction work will be carried out, affecting other traffic.

3. Transformation of Road Transport: Electricity, Data, and Robotics

Bus transport has traditionally been the most flexible but most polluting form of public transport. In ecological Helsinki, this is turned upside down: electric buses are emission-free, and AI optimizes their routes.

3.1 Electrification of the Fleet (BEV)

HSL’s goal is a rapid transition to electric buses. By 2025, the goal has been a 30 percent electrification rate, and electricity is often a requirement in new tenders.

• Impact on Urban Space: The silence and lack of exhaust fumes from electric buses allow for terminals to be built indoors (like the Kamppi terminal, but more widely) and for lines to be routed through sensitive residential areas.

3.2 Robot Buses: Holy Grail or Eternal Promise?

Autonomous transport (Level 4/5) is theoretically the “Holy Grail” of ecological public transport. It would eliminate driver costs (approx. 50–60% of operating costs), making frequent service profitable even during quiet times and in sparsely populated areas.

3.2.1 Helsinki Pilots – World-Class Testbed

Helsinki has profiled itself as a global testbed (Smart City Testbed).

• Kalasatama & Jätkäsaari: Several robot buses have been piloted in these areas (e.g., Sohjoa Baltic, FABULOS). For example, line 26R and the art project R-Bus have transported passengers as a “last mile” connection to metro stations. R-Bus was a particularly interesting experiment where the bus chose its route based on algorithms and “sounds of AI,” testing passenger trust in technology.
• Vuosaari: Line 90R operates from the metro station to Aurinkolahti beach, testing autonomous driving amidst other traffic.

3.2.2 The Arctic Challenge – The Biggest Practical Obstacle

Although pilots are successful in summer, year-round use faces a massive technical obstacle in Finland. Studies by VTT and other actors (e.g., ROADVIEW project) show that autonomous vehicles are currently “summer children.”

• LiDAR and Snow: Most robot buses navigate using LiDAR laser scanning. Snowfall and snow swirling from the road (“snow spray”) cause “noise” that the sensor interprets as an obstacle. The bus performs an emergency stop on an empty road due to a snow cloud.
• Covered Lines: Computer vision needs lane markings. When the road is covered in snow, the bus loses its location data.
• Conclusion: Until sensor technology (radar, thermal cameras, better AI) solves these problems, robot buses cannot reliably replace traditional transport in the Helsinki winter. This delays their large-scale adoption to the 2030s.

3.3 Demand-Responsive Transport (DRT): Back to the Future

Helsinki was a pioneer with the Kutsuplus service (2012–2015), which was technically functional but economically unsustainable due to too low volume. Now the concept is making a comeback.

• Current State 2025: In Kirkkonummi and Siuntio, demand-responsive local buses (e.g., lines 918, 919) are already operating under HSL, serving sparsely populated areas.
• Future: As algorithms develop and the fleet electrifies, “Mobility on Demand” can theoretically replace the private car entirely. The user orders a ride via an app, and AI dynamically pools trips in the same direction. If robot buses can be made to work in winter, this will change the cost structure of the entire transport system.

4. Water Transport: The Blue Highway Electrifies

Helsinki’s geography—a peninsula and a vast archipelago—offers huge potential for water transport. Unlike road construction, the “blue infrastructure” is already in place.

4.1 Autonomous Electric Water Buses (Callboats)

This is one of Helsinki’s most promising “Smart City” innovations moving from theory to practice.

• Concept: Small, electric catamarans ordered via an app (like Uber). They operate on an “on-demand” principle without fixed schedules.
• Economic Logic: In traditional archipelago transport, crew costs are 60–70% of expenses. The company Callboats and Forum Virium Helsinki have piloted a model where one captain remotely monitors five autonomous boats. This makes accessibility to small islands economically profitable, which traditional heavy ferries cannot achieve.
• Regulation: The biggest obstacle is legislation requiring a crew on board. However, pilots have shown the technology (360 cameras, sensors) to be more precise than human senses.

4.2 Electrification of the Suomenlinna Ferry

Traditional ferry traffic (Suomenlinna II) is being modernized. Electrification (retrofit) is an ongoing project that reduces emissions and noise in the sensitive areas of the Market Square and residential islands. The upgrade of ABB’s frequency converter technology has extended the lifecycle of the current fleet and improved energy efficiency.

4.3 Helsinki–Tallinn Tunnel: Shadow of a Megaproject

On a theoretical level, a railway tunnel between Helsinki and Tallinn is still being discussed.

• Theory: The tunnel would create a twin city (“Talsinki”), connect Finland to the European rail network, and dramatically reduce shipping emissions by shifting freight and passengers to rails.
• Practice: The project is stuck in funding negotiations, environmental impact assessments, and geopolitical uncertainty. Although private funding models have been proposed, the project is unlikely to materialize before 2040, and thus it is not a solution for the 2030 carbon neutrality goals.

5. Vertical Dimension: Urban Air Mobility (UAM)

When land and sea become congested, eyes turn to the sky. Helsinki is an active party in implementing the EU’s drone strategy (CITYAM, AiRMOUR projects).

5.1 Logistics and Emergency Drones

The first wave of “airborne public transport” does not carry people, but goods and vital services.

• Pilots: Helsinki has already tested transporting medical supplies from a pharmacy to the Laajasalo health center and flying defibrillators to emergency sites. Drones bypass traffic jams and cross bodies of water in minutes.
• Ecological Impact: Although drones themselves consume energy, they reduce the need for combustion-engine vans and couriers in the urban area (“last mile delivery”).

5.2 eVTOL – Flying Taxis: Future Premium Service?

Electric Vertical Take-Off and Landing vehicles (eVTOL) exist technologically (e.g., Volocopter, EHang).

• Theory: In Helsinki of 2030, there could be “vertiports” (e.g., in Pasila, Airport, Tallinn) between which flights are fast and emission-free.
• Practice: The EU and EASA regulatory framework (U-Space) is only just taking shape. Battery life, noise pollution in a dense urban environment, and safety standards mean that eVTOL traffic will not be mass public transport (like the metro) for decades. It will likely be an expensive premium service or for official use (police, rescue).

6. Micromobility and the “Last Mile”

Future public transport is not just large vehicles, but an ecosystem integrating personal light vehicles.

6.1 City Bikes and Integration

HSL’s city bike system is a model example of integration. In the future:

• MaaS (Mobility as a Service): E-scooters and bikes integrate seamlessly into the HSL app. The user does not buy a bus ticket, but the “right to move” from point A to point B.
• Winter Use: The season is extended, and the fleet is developed for year-round use. This reduces the need for short car trips in winter.

7. Sustainable Urban Logistics: Public Transport for Goods

An ecological city moves not only people but also goods.

7.1 Cargo Tram

A theoretical model tested e.g. in Dresden (CarGoTram). Helsinki could utilize the existing tram network and depots during the night or outside rush hours to move goods from ports or terminals to brick-and-mortar stores in the center.

• Obstacles: High utilization rate of the tram network during the day and maintenance at night. However, in “Physical Internet” thinking, goods could travel among passengers in special compartments.

7.2 Logistics Hubs and Cargo Bikes

Helsinki is testing “last mile” hubs (e.g., along Baana), to which goods are brought by heavier vehicles and distributed by electric cargo bikes. Forum Virium pilots have observed that electric cargo bikes are faster and more efficient on the narrow streets of the center than vans. For example, the distribution of small supplies for construction sites (Würth case) has been successfully shifted to bikes.

8. Abandoned Visions and Theoretical Alternatives

To deepen the analysis, one must also look at what has been left unimplemented.

8.1 Personal Rapid Transit (PRT) – “Podcars”

PRT systems (small automated pods on their own tracks) were the great vision of the early 2000s.

• Why Abandoned? Helsinki has rejected the idea of a physical PRT network (rails/troughs) due to its high infrastructure cost and visual detriment. PRT’s capacity per square meter is poor compared to public transport.
• Evolution: The idea of PRT has become “virtualized.” Instead of building rails, robot buses and taxis are developed to use the existing road network. This is more flexible and cheaper.

8.2 Hyperloop

A theoretical capsule traveling in a vacuum tube (Helsinki–Stockholm/Turku). The technology is still at the experimental stage and is not a realistic part of Helsinki’s public transport in the coming decades. It represents “techno-fix” thinking, which distracts from improving existing, functional solutions (like train connections).

9. Synthesis: The Future System in 2035

The ecological Helsinki of the future does not rely on a single technological miracle, but on the seamless, data-driven interplay (multimodality) of different forms.

9.1 Modal Split and Hierarchy

In 2035, the transport system is hierarchical:

1. Trunk Network (High Capacity): Automated metro and an extensive light rail network (Vantaa Light Rail, Viima, Crown Bridges, West Trams) form the backbone carrying the masses quickly.
2. Feeder Traffic: Electric buses and (weather permitting) autonomous robot buses feed passengers to trunk network stations.
3. On-Demand: Autonomous Callboats water buses and demand-responsive minibuses serve the archipelago and more dispersed areas.
4. Micromobility: City bikes and walking handle the last mile.

9.2 Theory vs. Practice Summary

Transport Mode	Theoretical Potential	Practical Realism 2030	Key Challenge/Enabler
Light Rail	High: Replaces cars	Very High: Several lines realized	Urban development, funding
Robot Buses	High: Cost saving	Moderate: Winter problems limit	LiDAR technology, weather conditions
Autonomous Ferries	Moderate: Archipelago	High: Pilots promising	Legislation (manning)
eVTOL (Air Taxis)	Moderate: Speed	Low: Premium/Emergency	Safety, noise, price
Cable Car	Moderate: Cheap crossing	Abandoned (Laajasalo)	Wind, capacity, network effect
PRT (On Rails)	Low	Replaced by virtual PRT	Rigidity of infra and price

Helsinki’s future ecological public transport is electric, rail-based, and data-driven. The most radical innovations (air taxis, hyperloop) will likely remain on the margins or research desks, while “boring” but efficient improvements—such as the electrification of buses and the expansion of the tram network—produce the lion’s share of emission reductions. True intelligence (Smart City) is not in flying cars, but in the fact that a mobile app can combine the metro, an e-scooter, and an autonomous ferry into one seamless travel chain.