ABSTRACT
Each year, billions of dollars are spent worldwide to develop, manufacture, and operate transportation systems such as aircraft, motor vehicles, trains, and ships. These systems carry billions of tons of goods and billions of passengers annually from one point to another throughout the world. For example, as per the International Air Transportation Association (IATA), the world’s airlines alone carry over 1.6 billion passengers for business and leisure travel each year, and over 40% of world trade of goods is carried by air [1].
