From the rooftop of London’s original John Lewis, the mayor, Sadiq Khan, never knowingly underselling himself, laid out the changes in store for the Oxford Street below: “We want this street to overperform … We want a public realm that is world class, green, healthy and safe – but also increases footfall in the shops.”

Unveiling a £150m plan earlier this week to ban all traffic on the capital’s famous shopping street, the mayor suggested that the West End shopping thoroughfare could be revived to rival Times Square, La Rambla or the Champs-Élysées.

Less so perhaps, Bridgend town centre. Councillors in the south Wales town are unconvinced that pedestrianisation has worked its magic; and others in identikit high streets around Britain might be surprised at Khan’s faith and persistence in plans that were first aired and knocked back in 2018.

Also surprised was Westminster council, which had already started to implement its own £95m improvement plan with local businesses and residents, one which retained bus and taxi access along the 1.2-mile thoroughfare. The council – now Labour-run – has expressed grave concern over the sudden announcement and potential imposition of the scheme.

In a letter to Khan and Angela Rayner – the secretary of state who could grant the mayor sweeping powers to override objections – the Westminster City council leader, Adam Hug, listed 10 concerns with the pedestrianisation plan including increased congestion around the area, curbing bus routes, limiting access for elderly and disabled people, increased crime and security risks – not to mention compensation for work already under way to improve the street.

Broadly, Khan’s analysis that banning traffic could be the solution has the backing of most studies. Matthew Carmona, the professor of planning and urban design at the Bartlett School of Planning at UCL, said: “The research evidence shows that pedestrianisation schemes lead to significant benefits to retail.”

However, he warned: “Every circumstance is different and I know of no similar schemes to Oxford Street which is both a major shopping street, one of London’s most significant bus highways, and is surrounded on both sides by some of London’s most affluent neighbourhoods.”

Carmona suggested that London follow the lead of Times Square in New York (see below) and test some “quick and temporary interventions” first, such as barriers, seating, planting and road paint to divert vehicles.

“Personally I agree that we need a radical plan for Oxford Street, and as the nation’s high street we need to consider more than just the views of local residents when deciding what to do,” he said.

The mayor will need to consult widely before banning vehicles from London’s premier shopping street, said Steve Millington, the professor of place management at Manchester Metropolitan University, who has been involved in the UK’s High Streets Task Force, which is helping local communities revive their town centres.

“Not all pedestrianisation schemes work,” Millington said. “Everyone can recall a precinct that is windswept and empty. But, particularly in big cities such as Barcelona, Bangkok, Toronto and across Germany, overwhelmingly academic studies show that, if you plan and do it right with consultation, it increases footfall, sales and increases or maintains the value of [buildings] and reduces vacancy rates.”

“Where it has not worked, the commonality has been poor consultation,” he said.

As Alan Partridge famously knew, traders need access to Dixons and elsewhere – the kind of consideration that has hit mooted further pedestrianisation of towns from Southend to Paignton. The Devon town’s local authority is typical of many which kept traffic from high streets during the pandemic lockdown, but backed down after pressure from local businesses who were convinced it had hit trade.

Councillors in Bridgend in Wales have suggested removing pedestrianised streets, which were put in place in the early 2000s, as businesses in the town claim there has been a decline in footfall and a reverse in the scheme could support improvements in trading.

On Oxford Street, however, despite the reservations of Westminster council, London’s big retailers appear to be throwing their weight behind Khan. John Lewis and Selfridges, both fixtures of the street for more than a century, issued supportive statements.

While Marks & Spencer, whose own plans to rebuild their store at the Marble Arch end of Oxford Street have also been frustrated, were more nuanced. The M&S chief executive, Stuart Machin, said: “We wholeheartedly agree with Mayor Khan that urgent action is needed to give the nation’s most famous high street a new lease of life – and support his commitment to, once again, make Oxford Street the leading retail destination of the world.”

The view from abroad

La Rambla

In recent years Barcelona has earned a reputation for imaginative pedestrianisation schemes such as “superblocks” and more recently the “green axes” plan to increase green space that has been an instant success with residents and visitors alike.

Now, after years of debate and delays, attention has turned to La Rambla, the city’s famous thoroughfare. Work has begun to widen the central pedestrian section and reduce traffic to a single lane on either side, ultimately limiting access to residents’ vehicles and public transport. The current phase is scheduled to be complete by 2027 at a cost of €55m (£46m).

La Rambla was built on top of a stream and from the 15th century onwards served as a breathing space between the cramped, disease-ridden streets of Ciutat Vella on one side and El Raval on the other. Unlike Oxford Street, it has never been a place to shop, but rather somewhere to take a stroll, buy flowers and have a drink in a bar.

These days it is so overwhelmed by tourists that strolling is out of the question and the tree-lined boulevard is a focal point for the city’s numerous pickpockets and drug dealers. Road traffic has never been an issue on La Rambla and whether the scheme to reduce traffic will, as the planners claim, encourage residents to return to the city’s most emblematic street remains to be seen. Stephen Burgen in Barcelona

Times Square

With its giant animated billboards, theatres and throngs of tourists, Manhattan’s Times Square likes to bill itself as “the crossroads of the world”. For decades that crossroads belonged to cars. Not any more. These days the intersection of Broadway and Seventh Avenue belongs to pedestrians – and lots of them. About 330,000 people pass through Times Square each day, making it one of the most visited tourist destinations in the world.

In the summer of 2009, the then mayor, Michael Bloomberg, created a temporary pedestrian-only zone in Times Square. The change came after an increase in traffic accidents in the area but was also part of his ambitious plans to make New York City more pedestrian and cyclist-friendly.

Despite vociferous criticism from some New Yorkers, worried about the impact on its appearance, the plan proved popular and the first section of the permanent plaza was unveiled in 2014. The major obstacles to navigation now are the crowds, not the lanes of cars that used to pin people in. Long stone benches offer respite for weary workers on their lunch breaks and selfie-snapping tourists. Today Times Square is transformed. Dominic Rushe in New York

Champs-Élysées

Once a favourite promenade for Parisians, the eight-lane Champs-Élysées has in recent years been steadily abandoned by local people as popular stores and cinemas have given way to luxury boutiques and the avenue has become the preserve of wealthy tourists.

Campaigners have repeatedly warned that the iconic avenue has “lost its splendour”, falling victim not just to changing consumer habits but also crises including the gilets jaunes (“yellow jackets”) protests and the Covid pandemic.

A move towards pedestrianisation started with one car-free Sunday a month. Now, work is scheduled to start in the coming months on an ambitious €250m makeover of the Champs-Élysées aimed at turning the 1.2-mile stretch of central Paris into “an extraordinary garden”.

Unveiled in 2019 by local community leaders and businesses, the project was formally approved by the Paris mayor, Anne Hidalgo, in 2021 but postponed, bar minor changes, until after this summer’s Paris Olympic and Paralympic Games. Jon Henley in Paris