This frozen corner of the Finnish capital region is about to become a testbed for high-tech rail construction, urban reinvention and French engineering under temperatures that can sink well below zero.
A future-proof tramway between city hall and the runway
French construction giant Colas, via its Finnish subsidiary Destia, has secured one of the most ambitious infrastructure deals in Finland: the western section of a new 19-kilometre tramway in Vantaa, linking the historic Tikkurila district to Helsinki Airport.
The contract gives Destia work worth around €230 million in a first phase and up to €420 million over the full life of the project, out of a total tramway budget of roughly €750 million.
The line will run through existing neighbourhoods and zones earmarked for major redevelopment, acting as the backbone for housing, offices and services that city planners want to concentrate along the route.
One of the project’s technical centrepieces is a tunnel running underneath Tikkurila railway station, built while the station continues to operate. Trains will keep running overhead as workers dig and pour concrete below, a logistical ballet that leaves no room for error.
Beyond the tracks themselves, the tramway triggers a full overhaul of public space. Engineers will rip up and rebuild roads, lay new bike lanes, and renew the dense mesh of underground utilities: drinking water pipes, sewers, power cables, data lines and telecom ducts.
The tram is less a stand‑alone transport scheme than a wholesale reset of Vantaa’s infrastructure, stitched directly into Finland’s national rail network and airport hub.
Vantaa aims at 2050 with rails as its backbone
Vantaa, long seen as the quieter neighbour of Helsinki, has grown into a strategic hub that mixes logistics, aviation, services and housing. Home to more than 250,000 residents and over 10,000 companies, it already ranks as Finland’s fourth-largest city.
Local authorities have set sharp targets for 2050: they want to accommodate around 60,000 extra inhabitants and create 30,000 new jobs along the tram corridor. The Aviapolis business zone near the airport is one of the fastest-growing economic areas in the country, and the new tram is designed to funnel people into and through it with less reliance on cars.
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- New housing clusters planned around future tram stops
- Commercial and office developments concentrated along the line
- Direct, low‑carbon access to Helsinki Airport
- Stronger links between suburban districts and national rail services
For city planners, the tramway is a tool to shape growth, not just respond to it. By fixing the route decades ahead, the project sends a clear signal to developers about where infrastructure, services and foot traffic will concentrate.
Building a flagship line at −15°C
Destia is no stranger to complex metro and tram sites in Finland. The company previously worked on the Kalasatama–Pasila public transport project in Helsinki, which also involved construction in a densely populated environment.
Vantaa pushes those constraints even further. Work will continue through winters where the thermometer can stay near −15°C for days, making concrete casting, earthworks and utility installation more delicate.
At those temperatures, concrete can crack if it cools too fast, water pipes can freeze solid, and wind can shred protective covers in minutes.
This forces the project team to plan around micro‑weather windows, use heated enclosures and carefully timed pours, and shift some tasks into warmer seasons. Coordination with train operators at Tikkurila adds another layer of complexity, as closures must be minimal and usually scheduled overnight or during short off‑peak windows.
French engineering, Nordic discipline
For Colas, the Vantaa tram is a showcase contract in a region where long winters and demanding public clients test every aspect of a builder’s capability. The group runs around 45,000 sites a year worldwide and posted turnover of roughly €15.9 billion in 2024, but Nordic projects have a special place in its strategy.
The company has built a reputation as a “special forces” contractor for tough environments. Its track record ranges from freight lines in the Saudi desert to roads over Alaskan permafrost, via airport runways in remote parts of Canada and tunnel refurbishments in the French Alps.
| Country | Type of project | Challenging environment | Technical focus |
| Saudi Arabia | Haramain freight railway | Heat above 50°C | Track stability on desert ballast |
| Canada (Quebec) | Runway rehabilitation | Polar winter, remote access | Material deliveries via ice roads or airlift |
| Alaska | Highway sections | Permafrost terrain | Ground insulation to stop thaw‑related sinking |
| New Caledonia | Port infrastructure | Cyclone‑prone region | Storm‑resistant structures, weather‑dependent schedules |
| France (Alps) | Fréjus tunnel upgrades | Confined, high‑risk setting | Ventilated works with tight safety windows |
This portfolio of “extreme sites” is one reason Finnish authorities were ready to hand Colas and Destia such a sensitive contract: tunnelling under an active station and working next to an international airport demand both technical rigour and the ability to adapt on the fly.
Why Finland is betting on tramways, not just metros
Vantaa’s project also illustrates a broader shift in northern Europe. Instead of relying solely on heavy metro lines and buses, cities are reviving tramways as mid-capacity, street-level systems that can reshape districts more gently.
Trams usually cost less per kilometre than underground metros and can open in phases as sections are completed. They provide predictable service and fixed stops, which developers often prefer to bus routes that can move or be cut.
For a fast-growing airport city like Vantaa, a tram offers a balance: serious capacity, a visible commitment to public transport, and enough flexibility to weave between existing buildings.
The climate angle also matters. Finland wants to cut transport emissions, and shifting daily commutes and airport access from cars to electric trams fits that agenda. The project will likely feed into future low‑emission zones, parking policies and cycling networks around the line.
Risks, trade‑offs and what could go wrong
A project of this scale carries real risks, both political and technical. Cost inflation for materials, labour shortages and unexpected issues under the station or streets could push up the bill or delay opening.
There is also a social risk: if property prices rise too fast along the line, some long-time residents may feel pushed out. Managing rent pressures, affordable housing quotas and local services will be just as decisive as track quality.
Construction impacts can also test public patience. Extended noise, traffic diversions and dust may last for years in some areas. Finnish cities are used to long winters, but not all residents enjoy waking up to jackhammers at dawn. Communication campaigns, clear timetables and visible progress on sections already finished can soften the blow.
What “extreme construction” really means on site
The Vantaa tram gives a concrete example of a term often used in marketing but rarely explained: extreme construction. On this project, it breaks down into a series of very practical constraints that shape day‑to‑day life on site:
- Careful scheduling of concrete pours to avoid cold snaps
- Use of heated tents and insulated formwork
- Backup power to prevent curing systems from shutting down in storms
- Contingency plans for airport‑related security protocols and access checks
- Continuous monitoring of ground movement above the tunnel under Tikkurila station
Each of these measures adds cost and complexity, but they reduce the risk of structural defects, accidents or operational disruption for trains and flights. For clients, that trade‑off often looks cheaper than dealing with a failure later.
For other cities, especially in colder parts of North America or Asia, Vantaa will serve as a live case study. If the tramway opens on time, copes well with ice and snow, and triggers the promised wave of investment along its route, expect similar airport‑linked tram projects to surface where runways and suburbs sit side by side.