State Road 37 (SR 37) is a major route in the U.S. state of Indiana, running as a four-lane divided highway for 110 miles of its course.At one time, the route ran from the southwest corner of the state to the northeast corner. In the pre-Interstate Highway era, Indiana 37 was the most direct route between Fort Wayne and Indianapolis. Interstate 69 has supplanted it as a through route, and State Road 37 now consists of two disconnected segments.