GRAMMY award-winner Petula Clark famously sang that the "lights are much brighter" downtown, but the coronavirus pandemic may change city centres across the world, as more people choose to work remotely and companies ditch large office towers.
With more than 6.3 million people reported infected globally, lockdowns to stem the spread of the respiratory disease in major cities have forced millions to work from home.
Many may never go back to working full-time in offices.
Twitter has said some of its employees can work from home "forever", while Google and Facebook employees can work remotely until next year. Big banks have indicated they may not fully occupy their office towers in London and Manhattan.
"In the aftermath of Covid-19, the cityscape may see changes as people and organisations embrace a new way of life," said Ethan Hsu, head of real estate firm Knight Frank Singapore.
"There could be radical shifts in the way cities and business districts are designed for a modified norm, which could include a reduced physical office footprint," he told the Thomson Reuters Foundation.
More than two-thirds of the global population is forecast to live in urban areas by 2050 - up from 56 per cent today, according to the United Nations.
Past epidemics led to massive changes in city planning and infrastructure, including sewage systems and public transit, as well as housing regulations.
With the coronavirus, cities from Amsterdam to Sydney have unveiled measures to improve sustainability, food security and mobility, with more green spaces, wider pavements, bicycle lanes and new technologies to ensure social distancing.
City centres are key economic hubs, with their mix of offices, shops, restaurants, bars, entertainment centres and residences. They are generally well connected by transit systems, and command some of the highest real estate values.
Remote working was already on the rise in many parts of the world before the pandemic. Now, as firms grapple with social distancing rules that limit how many workers can return, they are thinking about what their offices are really for.
That in turn will force planners and city officials to reconsider and redesign central business districts, said Tony Matthews, a senior lecturer in urban and environmental planning at Australia's Griffith University.
"If daytime working populations fall, new populations are likely to be needed to keep these areas buzzing and generating incomes," he said.
"Some areas may need to be redesigned if they are no longer economically viable - retail districts, for example. Some office buildings may be demolished or repurposed, with the surrounding infrastructure and public space also changing in time," he said.
There is precedent for this sort of urban transformation, Matthews added, with cities across the world having converted old industrial structures and decrepit waterfronts into art galleries, cafes, apartments and lively entertainment spaces.
One such example is London's Canary Wharf, once the world's largest port, that was redeveloped into a pricey financial district in the 1980s and 1990s.
The 97-acre (39-hectare) area, with the regional headquarters of several banks, may be in for another makeover, with Jes Staley, chief executive of Barclays, saying that the notion of putting 7,000 people in a building "may be a thing of the past".
In New York, the Sept. 11, 2001 attacks led to a decentralising of office spaces from the downtown area.
In Singapore, where the central business district normally heaves with crowds packing its chic bars and restaurants into the wee hours, most employees want to continue working from home after the lockdown is lifted on June 1, a survey showed.
That would mean less traffic and fewer people taking public transport at peak hours, which may lead to more mixed-use developments and amenities to draw footfall, said Mr Hsu.
"Fewer road-users would mean some space could potentially be freed up for other uses, such as wider foot and cycling paths, parks, event venues and outdoor activity spaces," he said.
In Washington DC, recommendations in ReOpen DC - a plan for reopening the city - include allocating sidewalks and streets for residents and restaurants, and temporarily repurposing vacant private spaces.
With "historical inequities" exacerbated by Covid-19, any plan must ensure that everyone has equal access to affordable housing, healthy food, and community facilities, it said.
More people working from home "will have a detrimental economic impact on the city," said Anjali Mahendra, director of research at the WRI Ross Center for Sustainable Cities.
"However, in trying to balance public health and economic concerns, cities are considering strategies such as moving business outdoors as much as possible, redesigning street and kerb space, using parking lanes to create bike lanes," she said.
With more people using a combination of walking, biking and public transit, "investing in bicycle, pedestrian and micromobility infrastructure can fill essential gaps in last-mile access to public transit now and in the future," she said.
"It presents an immense opportunity to restructure the transport system to serve the majority," she added.
In the longer term, while cities will still retain their economic centre in the downtown area, there will be a push toward decentralising commercial activity and for setting up business clusters outside of the city centre, said Mr Hsu.
"There will be greater pressure on master planners to re-think urban design to respond to changing lifestyles and behaviours," he said. REUTERS