To provide urban center level estimates of the proportion of population that has convenient access to public transportation.

To provide urban center level estimates of the average share of the built-up area of cities that is open space for public use for all.

To provide a framework of public-health-focused air quality indicators that quantifies country trends in exposure to major air pollutants.

To provide populated place (point) data with consistent population estimates.

To provide populated place (point) data with consistent population estimates.