The Interstate Highway System was widely accepted by America. As more roads were build, more car beyond the government’s expectations began to use them. The congestion was a problem before Congress passed the Federal-Aid Highway Act of 1956 on the highways, then increased more after. It was difficult for the highways to keep up with the motorists demands. For example, Indiana tried to raise gas-tax in effort to build its highways more quickly. The Act was modified to the Federal-Aid Act of 1968 increasing the expansion to 42,500 miles and again in 9173 to 43,000 miles. Funding was no longer the issue, now it was matching the expansional needs of motorist.
Public Roads, “The Highway Networks,” Febuary 2006, US Department of Transportation, March 17, 2009, <http://www.tfhrc.gov/pubrds/>.