By 2040, the need to quickly make high volume, low cost accommodation in megacities will favour mega-buildings that will be up to 10km tall, acting as miniature cities in their own right, probably pyramid-style, with residential, business, shopping, social, cultural and recreational areas or layers. Transport pods will be able to navigate up the sides to entry points and then through the structure to destinations.
Spaceports will be up to 30km. Building materials will be dominated by carbon variants, so frames would be very lightweight with far more glass and less steel or concrete.
Almost all transport will be driverless by 2040 and even self-driving cars will be being replaced by driverless pods that will be propelled and routed by linear induction mats on the road surface and on the sides of buildings. These pods need no wheels or engines, nor any significant IT on board other than the cloud-based IT that is omnipresent.
Plastic or fibreglass, lightweight, nesting together touching or millimetres apart, these will provide extremely rapid travel from door to door as well as deliveries. There will be many more robots by 2040, doing a wider range of jobs, and still plenty of drones.
Robots will take many forms depending on function, but there will be many androids already by 2040 that will act as friends, assistant, servants and workers. These will take part in social and cultural activities along with people.