In 1913, Henry Ford introduced a conveyor-based assembly line to America for the first time at Ford's Highland Park plant, located in Michigan. The Highland Park Ford Plant Factory was a manufacturing plant of the Ford Motor Company, founded in 1903. The assembly line benefited the company and changed worker productivity by reducing production costs and assembly times. For example, “Ford's famous Model T was assembled in ninety-three minutes” (History of the Automobile). The assembly line boosted the American economy, and when the Ford Motor Company lowered the price of the Model T, it made it more affordable for most Americans. Today, cars are easily accessible to everyone, everywhere. Most Americans can drive, take a bus, call a cab, or share a car with friends. Usually caught up in their daily activities, the thought of conservation slips from the mind. Due to automobiles, air pollution, human health, and car accidents have been adversely affected. According to the U.S. Environmental Protection Agency (EPA), more than half of air pollution in the nation is caused by mobile sources, primarily automobiles. The ozone layer on earth is found in the upper atmosphere and helps protect life on earth from the sun's strong ultraviolet rays. Although ozone provides a protective shield in the stratosphere, at ground level it is a harmful pollutant and is depleted by human activities. EPA authorities also state that “substances that contribute to ozone depletion usually have high concentrations of chlorine or bromine atoms and include chlorofluorocarbons or CFCs, halons, methyl bromide, carbon tetrachloride, and methyl chloroform.” Previously unaware of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and… the center of the paper… the ozone layer. Works Cited “Cars, Trucks, and Air Pollution.” Union of Concerned Scientists. Convio, September 03, 2013. Web.February 24, 2014. “CDC Study Finds Annual Cost of Motor Vehicle Accidents Exceeds $99 Billion.” Centers for Disease Control and Prevention. August 2010. Web. 2 May 2014. “Clean cars, air pollution and human health”. UCUSA. Mobify, September 9, 2013. Web.03 March 2014. “Car Accident Cost and Statistics.” RMIIA. Rocky Mountain Insurance Information Association. Network. 20 February 2014. “Cars and ozone”. US Environmental Protection Agency. January 1993. Web2 May 2014. King, Jennifer. “How does car pollution affect the environment and the ozone layer?” SFGate. Hearst Newspaper, ND. Network. February 18, 2014"While you're on the road this holiday season, be on the lookout for drivers who don't have Internet access."State Farm. November 16, 2012. Web. May 2 2014.