One of the many unintended consequences of 9/11 was a significant increase in the amount of car and truck crashes in the year after 9/11. It has been estimated that approximately 1,600 extra motor vehicle deaths occurred in the year after 9/11 due to people being afraid of flying and choosing to drive instead.
To give you some perspective, the risk of being killed in a car or truck accident in the United States in any given year is one in 7,000. But dying of cancer is one in 600 and dying of heart disease one in 400.
In 2010, the number of people killed in car accidents in the United States was 32,885. In the year 1972, the number of deaths was 54,589.