Four-wheel braking from a common foot pedal was introduced, as was the use of hydraulically actuated brakes. Towards the end of the vintage era, the system of octane rating of fuel was introduced, allowing comparison between fuels. In 1923 the gasoline additive Ethyl made its debut at the Indy 500 that resulted in a boost in octane from the 1950s to the 1980s In the United States drive-in restaurants were introduced as well as suburban shopping centers and motels. Alfred P. Sloan and Harley Earl of General Motors, and Walter P. Chrysler capitalized on advertising the automobile’s role in the life of the consumer for more than just the utilitarian value compared with the horse. The stock market crash of 1929 started the layoff of automotive workers and many new companies went bankrupt but over two million cars were still produced in 1929 and 1930. The Federal Aid Road Act of 1916 was the first federal highway act. War and lack of funding hampered any positive results of this act. The Federal Aid Highway Act of 1921 (Phipps Act) started a 50/50 matching fund to states for road building and resulted in the creation of new and improved roads. During this period as well as the car adapting to society, there were better roads, and society began to adapt to the car. Dwight D. Eisenhower participated in the highly publicized Transcontinental Motor Convoy in 1919 and after becoming President the experience influenced the Federal Aid Highway Act of 1956 that included 41,000 miles of highways. The end of World War I brought about the “Depression of 1920-21” with an inflation rate of over 20 percent, a 7 percent Federal Bank discount loan rate, and an 11.7 percent unemployment rate, that resulted in many companies going bankrupt and the automotive industry was decimated.