The section of La Diagonal between Plaza Francesc Macià and Plaza de las Glòries will be partly closed to vehicular traffic from 9am to 5pm on Sundays and public holidays on a trial basis as authorities in Barcelona look to open up the city to pedestrians.
Lanes of the iconic Passeig de Gràcia are also set to be closed to cars during the same hours between Cinc d'Oros, where Passeig de Gràcia meets La Diagonal, and Gran Via.
The trial closures will come into effect by March at the latest, according to Catalan daily La Vanguardia.
Instead of cars, those section of the streets closed to cars will be filled with seats, tables and deckchairs, under the ambitious plans. A large section of La Diagonal will also become a de facto part with a programme of cultural events laid on.
If the trial closures are a success, other streets will be incorporated into the plans, Barcelona's town hall has said.