What are the biggest design challenges facing urban areas?

None of the designs suggested by Terreform. As presented in the video, the group is a perfect example of why architects should not attempt urban or regional planning - they just don't (often) have the background for it. The basic problem here is they seem not to be changing the current model of urban development at all, and I suspect they also mistakenly equate mobility with access. Due to the extent of energy problems, population size increase and climate and ecological disruptions, planning now requires following the precautionary principle and preparing for the worst, not dreamily thinking about the next big technological fix.

America, with it's current flock of politicians, will spend our future hunting for rats to eat in our burned out urban areas. I suggest .22 rifles loaded with bird shot over baited sites from ground blinds as the best coarse of action.

Then there's cannibalism which while gross to most of us now; we may see a day when a fine Republican properly gutted and slow grilled over a spit may go very well indeed-----------

We need vehicles that are solar powered to reduce pollution and to be free from never stop hiking price of gasoline.

Simple:

Housing, which should go vertical to free up arable, percolating land and facilitate maximum carbon consuming and oxygen producing vegetation.

Fast, safe, and clean energy efficient mass transportation, to reduce the need for more paved over earth and co2 emmissions.

Vertical parking to also free up arable, percolating land and facilitate maximum carbon consuming and oxygen producing vegetation.

Abundant and sufficient carbon consuming green spaces to help cool, clean, and oxygenate the air in cities, and provide green corridors for wildlife needing to move about and ensure genetic diversity among the animals.

why do you want to know? is this a question in a vacuum? or is it about a show or something?

Maintaining a sense of community, ease of access to groceries, transit and public space, and some semblance of privacy. Trash removal and a clean water supply are also important.

design challenge:

moving bodies and still have a semblance of living on earth

I think the biggest challenges will be re-introducing useful green space to more densely populated areas and not losing the flavor of the community when adding new buildings or transit options.

Car owners unwilling to give up their precious free parking spots for safer bike lanes. Not that I'm biased ;-)

the upfront costs for effective public transportation

The buildings are in the way! Tear some down and make a highway!

They old designs when cities relied on differenct types of transportation

Quite Simple:
Smaller cars.
Make them run with something that is not running out, like water or sunlight or air. All of that tech is out there but noone is using it.

Respect for the planet is essential otherwise we will always have a deep impact in our environment and therefore in our lives.

As a car company, you guys should be focusing on getting new technologies out there. Money will just flow when you are aligned to a human dream where we can respect our surroundings.

It's the suburbs that are going to suffer most as oil production continues to peak and decline.

Getting rid of cars.

low income housing