Slate.com

Cities are struggling with the right way to control bicycle traffic in a system built for cars. Should bicycles act like cars? Or should roads change to meet the special needs of bicycles?

The relationship between poverty, poor health and obesity is complex, writes Daniel Engber. However, research is showing that "obesogenic" environments and social inequality play leading roles in all three.

Solar-powered trash compactors, while not cheap, pay for themselves relatively quickly. With state and city budgets more liquid thanks to stimulus money, municipalities are snapping them up.

Mohamed Atta, one of the 9/11 terrorists, pursued a masters degree in city planning before the attacks. Slate's Daniel Brooks reads Atta's masters thesis, and finds a strain of anti-Western modernism that is revealing.

Witold Rybczynski provides an illustrated history of airport architecture on Slate [Slideshow].

They're safer, faster, require less fuel use and enhance public space. So why do Americans tend to reject proposals for roundabouts?

While it didn't transform personal mobility and lead to the redesign of urban areas, the Segway has found some unexpected forms of popularity.

How did high ceilings become equated with high class?

Author Tom Vanderbilt suggests that train service has been headed in the wrong direction for the better part of a century.

More homeless people are squatting in abandoned suburban housing. Eduardo M. Peñalver, co-author of the forthcoming book "Property Outlaws" thinks cities should acquire these properties and allow the former owners to live in them as renters.

Witold Rybczynski reports on a recent conference at the University of Pennsylvania at which planners emphasized technology. He thinks that there is more to it than that.

After seemingly endless expansion, Starbucks begins closing some 600 stores, prompting a "save Starbucks" campaign.

Witold Rybczynski visits Thom Mayne's new Federal Building in downtown San Francisco. He finds a number of energy conservation innovations at play, but concludes that precious little else is playful or human about the architecture.