According to a new vision of the future set out today, stackable electric cars and 'telepresence' screens are just one generation away. The study, Megacities on the Move, suggested ways to overcome transport infrastructure in huge urban spread.
One idea is electric cars that can be nested together like shopping trolleys, available for people to hire from a station in one part of a city and then drive to another.
Or, if everyone owns electric cars, the stations would instead contain charged batteries that people would be able to exchange for empty ones.
Similarly, telecommunications that enable people thousands of miles away to appear in a room, as if they were there in person are being pioneered in California.
The report also carries a severe warning: that unless action is taken now large cities risk becoming "dysfunctional environments, where people face extreme deprivation, shortages of food, water and energy, and are vulnerable to floods, heat waves and other impacts of climate change".
"We are seeing the largest migration to cities in history. How those cities develop today will lock in behavior for decades to come," the Scotsman quoted Peter Madden, chief executive of the forum, as saying.
"The future wellbeing of billions of people depends on the action we take now. The global race for sustainability will be won or lost in the streets of our megacities."
The report will go to governments, city authorities and businesses to help them understand challenges of the future and develop strategies for people to live and travel more sustainably in the major cities of the 21st century.
A Scottish Government spokesman said, "Scotland will undoubtedly develop to adapt to new and ever changing ways of living, working and travelling - for instance electric vehicles are likely to play a key role in future transport, run solely on electricity from the grid provided by a network of charging points."