Logistics and the structure of a persons lifestyle....Alternative forms of transportation may not be practical because of location and lifestyle of an individual....or an individual has absolutely no interest in giving up their car and using public transit or bicycle.....Seriously it has nothing to do with any obstacles, it all comes down to personal choices on where the person wants to live and what they want to use to get around...After all it's 21 century and we're not living in a third world country so there is nothing unusual about being modern using a car to get to work, it's common sense that majority of people will choose the easiest, most convenient and most comfortable way to get around.