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.
New York State Thruway
The New York State Thruway system is a collection of six individual components across the state of New York that connect the state to four neighboring states (Connecticut, Massachusetts, New Jersey, and Pennsylvania) as well as the Canadian province of Ontario. Together, the highways extend for , making the Thruway system one of the largest toll highway systems in the United States. The longest of the six components is the mainline. Of the 570 miles in the Thruway system, (98.4%) carries at least one Interstate Highway designation. Only three sections of the system are not part of the Interstate Highway System; these are the Garden State Parkway Connector in Rockland County, a portion of the Berkshire Connector between its western terminus at exit 21A on the mainline near Selkirk and where it joins up with Interstate 90 at exit B1 near Castleton-on-Hudson, and a short section of the mainline within exit 24 in Albany that is located between where I-87 departs the roadway and I-90 enters it. They are designated as New York State Route 982L (NY 982L), NY 912M, and NY 915H, respectively, all unsigned reference routes. The speed limit, enforced by the New York State Police, is 65 miles per hour along most of the Thruway.