A spur route in the United States Interstate highway system refers to a branch off of a primary interstate that connects with a destination away from the primary interstate. A spur route is distinct from a bypass or a beltway (or loop) in that it does not reconnect with the primary interstate. However, like bypass and loop routes, spur routes have a 3-digit route number in which the last two digits are that of the primary interstate. Spurs can be branches off of other highway types too (e.g. US highways, state routes, etc.).