US Interstate Highway System. Still, at least as of 2007, none of such highways funded by the Interstate Highway program were planned or built to the standards of the Interstate Highway System. As of March 2001, Puerto Rico had of such roadways. As of 2001, there were three highways in Puerto Rico funded under the Interstate Highway Program. For obvious reasons, these routes—as with Interstate Highways in Alaska and Interstate Highways in Hawaii—do not connect to the Interstate Highway System in the contiguous United States. Like Interstate routes in Alaska, Puerto Rico Interstate routes are unsigned. For administrative and funding purposes, the three routes have been designated as PRI-1, PRI-2 and PRI-3 and run along various combinations of Puerto Rico routes. They do not follow the even-and-odd-number rule used in mainland United States that indicates direction of travel. Per Section 103(c)(1)(B) (ii), Title 23, United States Code (23 U.S.C.) Puerto Rico is exempt from the design standards of Section 109(b). Puerto Rico's Interstate routes should not be confused with Puerto Rico Routes PR-1, PR-2, and PR-3, which are other major highways in Puerto Rico. See also List of highways in Ponce, Puerto Rico 1953 Puerto Rico highway renumbering Notes References External links 2020 Manual de Rotulación para las Vías Públicas de Puerto Rico Puerto Rico Road Photos Highways