- 1910s Till The 2010s — 100 Years Evolution Of Traffic

: The 20th century saw the creation of massive road networks, like the U.S. Federal-Aid Highway Act of 1921 , which paved the way for expansive interstate travel.

: In the 1930s, the first barrier crash tests were conducted by General Motors . 100 Years Evolution of traffic - 1910s till the 2010s

Traffic signals: A brief history | Washington State Magazine : The 20th century saw the creation of

As vehicle speeds and fatalities rose, governments shifted focus from driver behavior to vehicle engineering. 100 Years Evolution of traffic - 1910s till the 2010s

: In 1908, Henry Ford introduced the Ford Model T , which became so popular that by 1914, he adopted assembly line methods to meet soaring demand.