During the years 2014-2017, the tram traffic of Tallinn experienced a throughgoing renewal. Renovation of tram rails Tondi-Ülemiste and Tondi-Kadriorg started in 2014 and in October 2015, after completion of the works , it was possible to run on new rails 70 tonnes weighing new modern CAF Urbos trams. Tallinna Linnatranspordi AS has bought 20 new CAF Urbos trams.
Including new trams, the project total cost was 103,5 million euros, of which 77,9 million euros was financed by the state, involving 53,3 million euros of greenhouse gas emission allowances. The next phase of tram rail and Kopli tram depot renovation started in 2016 and the works were completed in August, 2017. The depots were ready to serve new CAF Urbos trams. The project total cost was 20 million euros.
In 2016 started also the extension works of tramline No.4 to the Lennart Meri Tallinn Airport. A total of approximately 10,000 square meters of breaker-crushed limestone were removed in the course of the construction of the tunnel, which includes a 150-meter enclosed area and 125-meter-long ramp.
The biggest challenge of constructing the airport extension of the tram line was the need to route it under the existing railway and Suur-Sõjamäe Street without interrupting rail traffic. Tallinn airport tram line entered into service on 1st September, 2017 and makes the airport easily accessible.
Construction of the airport extension will cost a total of 12,5 million euros, of which 9,8 million euros was funded by the Connecting Europe Facility (CEF) and 2,7 million euros by the City of Tallinn.