Puerto Rico Highway 110 (PR-110) is a road that goes from Añasco, Puerto Rico to Aguadilla through Moca. It extends from Puerto Rico Highway 2 north of Añasco to Ramey Air Force Base.
Currently, PR-110 has two branches in its old segments in Aguadilla and Moca and it also has another one between the two municipalities.
Puerto Rico Highway 110R (, abbreviated Ramal PR-110 or PR-110R) was the old section of PR-110 through downtown Moca. This road can be seen as a Business 110, but currently is renumbered to PR-4025.
Puerto Rico Highway 4010 (PR-4010) is an old segment of PR-110 that provides access to a small residential area between Aguacate and Maleza Alta in Aguadilla. Previously it was identified as PR-110R.
Puerto Rico Highway 4110 (PR-4110) is a spur route of PR-110 between Moca and Aguadilla. It extends from PR-110 to PR-443.