Puerto Rico Highway 864 has a single lane per direction in the entire length and provides access to several neighborhoods of the western area of Bayamón.

[3] It begins at PR-2 in western Hato Tejas barrio and heads to the east, where meets with PR-862.

After PR-862 intersection, PR-864 continues to the east, passing through few neighborhoods until its end at PR-2 in eastern Hato Tejas.

[5] The current numerical designation corresponds to the 1953 Puerto Rico highway renumbering, a process implemented by the Puerto Rico Department of Transportation and Public Works (Spanish: Departamento de Transportación y Obras Públicas) that increased the insular highway network to connect existing routes with different locations around Puerto Rico.

The entire route is located in Hato Tejas, Bayamón.