State Road 18 (
SR 18) in the
U.S. State of
Indiana is an east–west route in North Central Indiana running from the
Illinois border in
Benton County almost to the
Ohio border, terminating at
U.S. Route 27 (US 27)/
State Road 67 (SR 67) in
Jay County. State Route 18 is mainly a 2 lane road with exception of 4 lane divided highway from Marion to
Interstate 69 (I-69). Marion is the only considerably large city that Route 18 passes through. State Route 18 runs just south of the lakes region, with Lake Shafer, Lake Freeman, Mississinewa Reservoir, and
Salamonie Reservoir not too far to the north. With the exception of Marion, Route 18 passes through mostly small towns. The terrain is mostly level and is utilized mostly for agriculture.