Innovative changes to the internal combustion engine, and therefore automobiles, represent one of the revolutionizing feats of the 20th century. Olds Automobile opened a production factory in Detroit in 1901, which was one of the first steps toward mass producing American cars. In the first year of production, 425 Oldsmobiles were built. In 1908, Henry Ford began producing his Model T cars and in the first year built 10,660 cars, a huge improvement from the Oldsmobile. Henry Ford modeled his assembly line process after the way Kiichiro Toyoda built his Toyota cars in Japan, a system known as lean manufacturing. General Motors (GM) was also formed in 1908 by William Durant.

Ford and GM would go on to be two of the main competitors in commercial vehicles, but in the 1920s, GM was just trying to keep up. No one was producing an engine better than Ford’s so Alfred Sloan, the man in charge of GM at the time, decided to produce better looking cars since he couldn’t make better functioning cars. Sloan changed what the body of his cars looked like and began releasing new colors every few years, providing buyers more options to choose from. This decision changed American consumerism because it established the standard of creating new products sooner than they were needed. Known as planned obsolescence, this process of constant improvements and changes has driven America’s economy, for better or for worse, as people became used to the idea of always purchasing new or updated things (phones, cars, clothes, watches, etc.) And once cars were being mass produced, it was a matter of time, money, and innovation from engineers to create cars as we know them today. There were plenty of new inventions including power steering, turn signals, vehicle airbags, and air conditioning. 

With more cars on the road, more roads needed to be built. These construction projects provided plenty of jobs in America, and in 1956, when President Dwight Eisenhower signed the Federal Aid Highway Act, 90% of new interstates were paid for by the government. By the end of the century, it was commonplace for every home to have a car.

Before the internal combustion engine took off, electric vehicles had a shot at the spotlight. In 1895 Thomas Edison made a prediction: “it is only a question of a short time when the carriages and trucks in every large city will be run with motors.” These motors ended up being gasoline and diesel engines, but in 1897 the best-selling motors were electric. Tom Standage details the electric vehicle’s false-start in his book, A Brief History of Motion: From the Wheel, to the Car, to What Comes Next. Combustion engines turned out to be more powerful and captured the market for new cars through the 20th century, but an unexpected byproduct of the internal combustion engine is increasing carbon dioxide in the atmosphere. 

It is important to consider potential  byproducts of new technologies, and as lithium-ion batteries are becoming the standard for electric vehicles, it will be especially important for engineers to think about potential downsides of extensively using them. Electric vehicles are decreasing the total carbon dioxide emission by cars in America, although the electricity they run on is primarily produced by gas-powered plants. Given what we’ve learned about unexpected outcomes, it will be important to think carefully about things that could go wrong as well as the benefits of changing the way people do things. The engineers of today and tomorrow will guide how people think about those things, and they will advise the government about possible regulations that could reduce harmful outcomes.