A project to build a roof and garden over part of the Regional Road adjoining the Sta Venera tunnels would cost €35 million, Energy and environment minister Miriam Dalli told parliament on Wednesday.
That is €15 million more than an estimate given by former minister Jose' Herrera in 2019.
The project was promised by the government several years ago following complaints of traffic noise by neighbours.
Nationalist MP Darren Carabott on Wednesday asked in parliament what progress had been achieved so far and whether the promise to complete the project by next year would be achieved.
Dalli said several studies had been made and it was concluded that the structure could be built. The project is being considered in greater detail. The project is estimated to cost €35m.