<Table> <Tr> <Td> </Td> <Td> The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject . You may improve this article, discuss the issue on the talk page, or create a new article, as appropriate . (August 2016) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject . You may improve this article, discuss the issue on the talk page, or create a new article, as appropriate . (August 2016) (Learn how and when to remove this template message) </Td> </Tr> <P> Suburbs typically have longer travel times to work than traditional neighborhoods . Only the traffic within the short streets themselves is less . This is due to three factors: almost - mandatory automobile ownership due to poor suburban bus systems, longer travel distances and the hierarchy system, which is less efficient at distributing traffic than the traditional grid of streets . </P> <P> In the suburban system, most trips from one component to another component requires that cars enter a collector road, no matter how short or long the distance is . This is compounded by the hierarchy of streets, where entire neighborhoods and subdivisions are dependent on one or two collector roads . Because all traffic is forced onto these roads, they are often heavy with traffic all day . If a traffic crash occurs on a collector road, or if road construction inhibits the flow, then the entire road system may be rendered useless until the blockage is cleared . The traditional "grown" grid, in turn, allows for a larger number of choices and alternate routes . </P>

Long commutes typical of the american suburbs have contributed to which phenomenon