Barcelona could cut deaths from air pollution and improve quality of life by implementing in full a plan to calm traffic and free up space for residents, researchers said on Monday.
The compact Spanish city is home to more than 1.6 million people and is plagued by contaminants and noise largely due to heavy density of traffic, as well as lacking greenery.
A study by the Barcelona Institute for Global Health (ISGlobal), published in the journal Environment International, found the city of Barcelona could prevent 667 premature deaths every year if it created 503 "superblocks" as first proposed.
The "superblocks" - which keep cars out of designated areas in the city and develop public space in streets - have been complex to roll out, with only six put in place so far.
"What we want to show with this study is that we have to go back and put the citizen at the centre of ... urban plans, because the health impacts are quite considerable," said lead author and ISGlobal researcher Natalie Mueller.
As a city with the highest traffic density in Europe, Barcelona also needed to make it easier for people to commute in from the wider metropolitan area by public transport, she added.
The projected reduction in deaths from the "superblocks" plan would be achieved mainly as a result of a 24% decrease in air pollution from nitrogen oxide (NO2), along with lower traffic noise and urban heat, the study said.
Data released on Friday from the Barcelona Public Health Agency showed air pollution accounted for 351 premature deaths in the city in 2018, around the same as in 2017.
Motor vehicles generated the main pollutant, with almost half the city's population regularly exposed to NO2 levels above the safe limit set by the World Health Organization, the city council said.
From January 2020, Barcelona will implement low-emission zones on weekdays, keeping 125,000 vehicles out of the city.
The city council will also declare a climate emergency including a package of urgent measures to cut down on private vehicle use and boost public transport, among other actions.
It has already extended cycle paths and upgraded its shared bike scheme, while shrinking on-street parking.
Barcelona City Hall told the Thomson Reuters Foundation it aimed to start drafting plans for three new superblocks shortly, as well as launching public consultations for others.
The ISGlobal study found that, besides reducing deaths, a full roll-out of the "superblocks" project would increase life expectancy by almost 200 days on average per inhabitant, and generate an annual economic saving of 1.7 billion euros ($1.9 billion).
The superblocks have sparked opposition in some local areas, notably among small traders who fear they could deter customers.
But Mueller said the concept was similar to banning smoking in bars and restaurants, which was initially unpopular but quickly accepted once people realised the benefits.
"Even if they don't see it in the beginning, often in the end they are quite happy," she said, noting the need for "courage" in public policy making.