Construction began on the airport extension of the number 4 tram last August which would eventually extend its tracks across Peterburi Highway, through a tunnel under the railway and Suur-Sõjamäe Street, and Keevise Street in Ülemiste City, terminating with a balloon loop at Tallinn Airport.

TLT board chairman Enno Tamm described the completed construction as one of the most complicated and innovative projects in recent decades.

Vikerraadio news broadcast "Uudis+" asked Tamm why the number 4 tram from Tondi and not the number 2 tram from Kopli was chosen to be extended to the airport if the latter would provide direct access to the airport from the trains at Baltic Station.

"First of all, if we had rerouted the number 2 instead, the opportunity would remain to ask why not the number 4 tram," Tamm replied. He also added that those who want to transfer from the train to the airport will simply have to switch trains at Hobujaama in the city center, which he found logical.

"There is not one city in the world with tram service where all trams go all places," he said. "For example, in Stockholm there is Stockholm Central Station, and everyone transfers there to the outbound train they need. And so transfers are a completely normal component of public transport network planning."

While the last tram departure from Tallinn Airport is currently scheduled for 12:37 a.m., according to Tamm, departure times are in no way set in stone.

"Tallinn Transport Department provides us with our schedules according to demand," he explained. "We have already previously discussed that we will extend the last departure from Tallinn Airport."

A total of approximately 10,000 square meters of breaker-crushed limestone and 6,000 square meters of excavated soil were removed in the course of the construction of the city's first tram tunnel, which includes a 150-meter enclosed area and 125-meter-long ramp.

1,000 square meters of concrete was poured or assembled, to which the tramways together with their supporting structure will add another approximately 700 cubic meters of volume.

The airport extension cost a total of €12.5 million, €9.8 million of which was covered by EU funding and the remainder of which was picked up by the City of Tallinn.