Indiana Code Title 36. Local Government § 36-4-3-1.5

Sec. 1.5. (a) For purposes of this chapter, territory sought to be annexed may be considered “contiguous” only if at least one-eighth ( 1/8 ) of the aggregate external boundaries of the territory coincides with the boundaries of the annexing municipality. In determining if a territory is contiguous, a strip of land less than one hundred fifty (150) feet wide that connects the annexing municipality to the territory is not considered a part of the boundaries of either the municipality or the territory.

(b) This subsection applies to an annexation for which an annexation ordinance is adopted after June 30, 2015. A public highway or the rights-of-way of a public highway are contiguous to:

if the public highway or the rights-of-way of a public highway are contiguous under subsection (a) and one (1) of the requirements in subsection (c) is satisfied.

(c) A public highway or the rights-of-way of a public highway are not contiguous unless one (1) of the following requirements is met:

A municipality may not annex a public highway or the rights-of-way of a public highway or annex territory adjacent to the public highway or rights-of-way of a public highway unless the requirements of this section are met.