whites still often inhabited vastly different neighborhoods. Redlining is the practice of denying or increasing the cost of services, such as banking, insurance, access to jobs, access to health care, or even supermarkets to residents in certain, often racially determined, areas. The most devastating form of redlining, and the most common use of the term, refers to Mortgage Discrimination. Data on house prices and attitudes toward integration suggest that in the mid-20th century, segregation was a product of collective actions taken by whites to exclude blacks from their neighborhoods. The creation of expressways in some cases divided and isolated black neighborhoods from goods and services, many times within industrial corridors. For example, Birmingham's interstate highway system attempted to maintain the racial boundaries that had been established by the city's 1926 racial zoning law. The construction of interstate highways through black neighborhoods in the city led to significant population loss in those neighborhoods and is associated with an increase in neighborhood racial segregation. The desire of some whites to avoid having their children attend integrated schools has been a factor in white flight to the suburbs, and in the foundation of numerous segregation academies and private schools which most African-American students, though technically permitted to attend, are unable to afford. Recent studies in San Francisco showed that groups of homeowners tended to self-segregate to be with people of the same education level and race. By 1990, the legal barriers enforcing segregation had been mostly replaced by indirect factors, including the phenomenon where whites pay more than blacks to live in predominantly white areas. The residential and social segregation of whites from blacks in the United States creates a socialization process that limits whites' chances for developing meaningful relationships with blacks and other minorities. The segregation experienced by whites from blacks fosters segregated lifestyles and leads them to develop positive views about themselves and negative views about blacks. Segregation affects people from all social classes. For example, a survey conducted in 2000 found that middle-income, suburban Blacks live in neighborhoods with many more whites than do poor, inner-city blacks. But their neighborhoods are not the same as those of whites having the same socioeconomic characteristics; and, in particular, middle-class blacks tend to live with white neighbors who are less affluent than they are. While, in a significant sense, they are less segregated than poor blacks, race still powerfully shapes their residential options.