List of Interstate Highways
There are 70 primary Interstate Highways in the Interstate Highway System, a network of controlled-access freeways in the United States. They are assigned one- or two-digit route numbers, whereas their associated "auxiliary" Interstate Highways receive three-digit route numbers. Typically, odd-numbered Interstates run south-north, with lower numbers in the west and higher numbers in the east; even-numbered Interstates run west-east, with lower numbers in the south and higher numbers in the north. Highways whose route numbers are divisible by "5" usually represent major coast-to-coast or border-to-border routes (ex. I-10 travels from Santa Monica, California, to Jacksonville, Florida, traveling from the Pacific to Atlantic oceans). Additionally, auxiliary highways have their numbering system where a different number prefixes the number of its parent highway.
Interstate 95
With a length of , I-95 is the longest north–south Interstate and the sixth-longest Interstate Highway overall. I-95 passes through more states than any other Interstate Highway at 15 states (as well as a very brief stretch in the District of Columbia while crossing the Potomac River), followed by I-90, which crosses 13 states. According to the U.S. Census Bureau, only five of the 96 counties (or equivalents) along the route are completely rural, while statistics provided by the I-95 Corridor Coalition suggest that the region served is "over three times more densely populated than the U.S. average and as densely settled as much of Western Europe". According to the Corridor Coalition, I-95 serves 110 million people and facilitates 40 percent of the country’s gross domestic product.