As auto traffic increases, people are less likely to walk or use bicycles because they don't feel as safe. The development of roads, shopping malls and superstores like Walmart also destroys local commerce. Small stores are among the first casualties of widened roads. The death of the corner store is one important aspect of urban blight. As neighborhood shops close, local jobs are lost, and the possibilities for local interaction decrease.
More crimes happen because there are fewer eyes on the street.
The mass production and use of automobiles in the 20th century has been an unmitigated social and ecological disaster. Continued mass car production and use of fossil based fuels is ecologically unsustainable. Auto traffic destroys cities and neighborhoods, while car accidents kill and maim hundreds of thousands of victims per year. Without adequate bicycle paths and public transit systems, the poor are deprived of access to jobs at the same time as they are forced to bear an unfair share of the social and environmental costs of the expansion of roads and auto travel. Make each neighborhood as self-sufficient as possible, providing living, shopping, recreation, work and cultural activities within compact areas to avoid forced travel.