Wikipedia:WikiProject U.S. Roads/Puerto Rico/National Highway System
- PR-1: PR-30 to PR-20, PR-18 to PR-26
- PR-2: PR-52 to PR-22, PR-165 to PR-1 (and via PR-165 to PR-22)
- PR-3: PR-1 to PR-53
- PR-10: PR-52 to PR-22
- PR-17: PR-18 to PR-26
- PR-18: PR-52 to PR-22
- PR-20: PR-1 to PR-2
- PR-22: PR-2 to PR-26
- PR-26: PR-1 to PR-66
- PR-30: PR-1 to PR-53 (and via PR-1 to PR-52)
- PR-52: PR-2 to PR-18
- PR-53: PR-52 to PR-3
- PR-66: PR-26 to PR-3
- PR-181: PR-3 to PR-17
Other routes in the primary network (not counting temporary connections around unconstructed freeways): PR-54