PR-1 starts in Ponce and ends in San Juan. The route connects important cities such as
Salinas,
Cayey, and
Caguas. In Ponce, PR-1 intersects
PR-2 and
PR-52. One of the major roads in Ponce that PR-1 does not intersect is
PR-10, which is accessible via an alternate route (
PR-5506) through
Mercedita Airport. A sign on PR-1 alerts drivers on where to get off to access PR-10. PR-1 passes through a small portion of the central town of Cidra, merely off the border with Cayey; the exit from PR-52 to Guavate is less than 1 hectometer from the town, and going north all structures and buildings off the road on the right are in Cayey, while the road itself and everything on the left is in Cidra until it enters Caguas just passing the junction with PR-787, which connects PR-1 to the rest of Cidra. This means that Cidra can be reached quickly from the main tollway (PR-52) via Exit 32 to Guavate. PR-1 is an undivided two-lane road, with some exceptions. In Ponce, it is a six-lane divided highway in its intersection with
PR-578 and PR-2 in
Sabanetas. There is a short segment in Cayey where PR-1 is also a divided highway. It becomes a divided road once again from Caguas to San Juan at a sector known as "La Muda". PR-1 is roughly parallel to PR-52 throughout its entire length. Prior to PR-52's inauguration, PR-1 was the route of choice from traveling between Ponce and San Juan. Bulevar Miguel Pou, mirando hacia el oeste, en Barrio San Anton, Ponce, PR (20181230 074625).jpg|PR-1 west in Ponce, heading towards downtown Ponce PR-1 Muda.jpg|PR-1 heading south from
San Juan to Caguas, near La Muda
Signing PR-1 is signed "PR-1 East" in the segment that travels from Ponce to Salinas, and then signed "PR-1 North" in the segment that travels from Salinas to San Juan. Likewise, the road is signed "PR-1 South" in the segment that travels from San Juan to Salinas and then signed "PR-1 West" in the segment that travels from Salinas to Ponce. ==History==