In a special message to Congress delivered on February 22, 1955, President Eisenhower listed the following reasons for embarking on highway construction:
1. Safety -- a need to improve the safety of America's road system. 2. Economics -- poor roads made motorists' costs higher and limited the nation's economic productivity. 3. National security -- Eisenhower gave this Cold War reasoning: "<span>In case of an atomic attack on our key cities, the road net must permit quick evacuation of target areas, mobilization of defense forces and maintenance of every essential economic function. But the present system in critical areas would be the breeder of a deadly congestion within hours of an attack." 4. Infrastructure for the future -- As America's economy grew, a better road system would be needed to support the nation's commercial activity.
The effects on American culture were significant. The </span><span>Federal-Aid Highway Act of 1956 was key to a period of dynamic economic growth in the USA. It also fueled the building of suburbs and a suburban culture -- which can be viewed as a good thing or a bad thing. Suburban culture had the tendency to segregate white Americans in the suburbs from blacks in the cities' inner core neighborhoods.</span>
Density is equal to the ratio of mass and volume. Mass is the amount of matter or substance of a body and volume is the space occupied by it. Density is the unit amount of matter or substance contained in unit volume.
