Which of the following was not an effect of the Federal-Aid Highway Act of 1956? It funded more than 41,000 miles of interstate highways.
It enabled faster transportation across the United States.
It added freeways to cities, encouraging the growth of suburbs.
It increased demand for shipping and railway transportation.

It increased demand for shipping and railway transportation.

Explanation:

The Federal-Aid Highway Act of 1956 was famously referred to as the National Interstate and Defense Highways Act. This Act was enacted by the 84th US Congress on the 29th of June, 1956 and signed into law by President Dwight D. Eisenhower.

The effect of the Federal-Aid Highway Act of 1956 include the following;

I. It was used to fund over 41,000 miles of interstate highways in the United States of America.

II. It enabled a faster means of transportation across the United States of America.

III. Freeways were significantly added to cities and as a result of this, it encouraged the growth of suburbs.