“This application is another step forward on the road to the virtualisation and decarbonisation of the transport system," José Mendes, assistant secretary of state for environment, told Lusa. "The idea is that it should be possible - taking secure steps and using Portuguese technology - to offer users the possibility of choosing the most suitable mode [of transport], choosing the kind of ticketing, the payment system that is t system 9ruly virtual."

At a ceremony in Lisbon to present the app, which is being developed by local company Nova Base, Mendes said that it could even persuade more people to use public transport.

“There is a range of drivers that will make it possible to attract more users for mass public transport, so that it is not a second choice, but the first," he said. "The step that we've taken today, this pilot concept of virtual payment through Via Verde [the existing virtual motorway toll system] is another little brick in this building that aims to attract more users."

The Via Verde Transportes app is to be installed on the user's mobile phone, with the price of the ticket for the trip on Carris buses or trams, the Lisbon Metro or on Transtejo ferries, being charged via Bluetooth.

Manuel Garcia, one of the 20 Nova Base staff that have been working on the project for the past two years, told Lusa that the app “will make the life of public transport clients easier” because it can, for example, calculate the best price for the passenger's chosen trip.

Although there is “some fine tuning” still needed - namely the installation of Bluetooth-ready equipment on board all Carris buses - the app should be available in the final quarter of 2017, Garcia said.

For Via Verde, Pedro Mourisca promised that the app will “change radically” the way that people travel, since it will no longer be necessary to “know the transport network or the hundreds or thousands of different tickets that exist" because the app will calculate the price "automatically".