More and wider roads increase runoff. More houses on larger lots reduces the amount of land that filters rainwater. Living in established cities and towns is more efficient and makes technological approaches to treating runoff possible. As scholar and urbanist Jane Jacobs notes, areas of higher density put more eyes on the street. According to Robert Moose, chief of police in Montgomery County, Maryland, community policing is aided by designs that include pedestrian-friendly streets, a diversity of housing types and densities, and a diversity of people of different ages, incomes and cultures.
Studies confirm that there is no cause-and effect relationship between crime and density.
In communities where houses are closer together and closer to shopping and services, traffic actually decreases. One recent study showed that doubling the density of homes reduces the total number of vehicle miles driven in an area by 20 to 30 percent. In these communities, people can do more without having to drive as far or as often. In these more compact communities, it is more cost-effective to create transportation alternatives like buses, light rail and sidewalks. The opposite is true.