Urban Access Across the Globe: An International Comparison of Different Transport Modes.
This impressive study by an international team of researchers, measured the number of jobs accessible within 30 minutes for four travel modes in 117 cities from 16 countries. They find that sprawled America cities provide modest automobile access and relatively poor transit and walking access; Australian and Canadian cities have lower automobile access, but better transit access; while Chinese and European cities tend to have the best overall accessibility due to their combination of compact development and intensive transport network. This indicates that access requires optimal combinations of density and mobility.