Access to affordable and efficient automobiles has a lot to do with urban sprawl. No longer were people confined to city transit systems which included buses and trains. Having an automobile meant that people could live far from their work and commute back and forth affordably. This is why the automobile is considered one of the main factors or causes for urban sprawl.
Not living in the major city centers created an opportunity for affordable housing. Homes that are just on the outer parts of the city limits were quite affordable as compared to the property or real estate in the city. Also, since demand was not that high, homes were extremely affordable and many people that were earning a decent amount of money could get more for their money.
Instead of feeling cramped in the city, people were beginning to prefer living in open spaces where you could own a house that had some land and distance between others. One of the major characteristics of urban sprawl is that the residences outside the major cities are much larger and provide for more space.
Living in polluted cities is not a healthy environment and many people began to notice the difference by moving outside the city limits. Fresh air and open spaces can do wonders for your health and many people just wanted to get out of the polluted cities for their health.
As the economic conditions began to improve over the past thirty or forty years, people that were earning and saving began to start a family. Having kids and raising them in congested cities is something that was seen as unhealthy. Kids need open spaces and schools that are not crowded. Urban sprawl began as couples with kids wanted to get away from the crowded city center and move out to the city limits so that their kids could have some room to grow.
As people began to earn a decent living and found that they were able to save some money, most wanted to invest in real estate as people began to move outside the city limits. Growth in home and property sales began to boom as people started investing outside the cities.