Across most of the US and Europe the average commute is almost always a half-hour:
Although population is strongly correlated with commuting time, particularly when all metro areas over population one million are included in the sample, the differences are surprisingly small. Orlando, with an urbanized area of only 600 square miles, has a mean commute just twelve seconds shorter than Dallas, which covers 1,780 square miles, although both cities have comparable densities, employment centralization and highway miles per capita.
Tim De Chant explains why urban planners may not be able to shorten our commutes:
Simply increasing density in some cities may shorten commutes for a brief period, but the honeymoon won’t last forever. … If we offer faster and better transportation, people will use it until it becomes overburdened. At which point they’ll just move closer to work.
The Dish 