The fourth and last portion of this project, Phase IV will consist of a stretch between PR-163 (intersection with PR-500) and PR-2 via improvements to the existing 4-lane Avenida Baramaya roadway.

[14] Additional 2017 delays were incurred after three landslide that occurred in the summer of 2017, requiring new analysis work to discover the causes plus the required additional design follow-up work to correct the discovered faults.

[12] By November 2019, it was reported the cost of this phase had increased to $56.5 million, "almost $20 million over the originally budgeted amount," much of this increased cost resulting from heavy damage by the 20 October 2017 Hurricane Maria, and a new end-of-work projected date of December 2021 was forecast.

[12] In January 2020, after the 7 January 2020 earthquake, the regional director of the Autoridad de Carreteras y Transportación stated that this section under construction had sustained damages from the quakes, and that its completion, which was already 49 months behind schedule, would now not be ready until December 2021 "at the earliest".

[15] In October 2012, the Puerto Rico Department of Transportation and Public Works revealed that the last track of PR-9, one that would connect PR-10 to PR-52 and consisting of 2.6 kilometers,[c] was soon to commence construction at a cost of $46 million.

In February 2015, the section from PR-123 to PR-132 was initially projected to cost $38.5 million and was planned to be ready in 2016.

[16] In May 2019, however, it was revealed by ACT that the project failed to meet the 2018 date due severe damaged caused by the September 2017 Hurricane Maria.

[18] In November 2019, it was reported that 75% of the work required for Phase III had been completed and an estimated opening date of September 2020 was being anticipated.

[12] In January 2020, after the 7 January 2020 earthquake and while discussing delays to phase II of the project (PR-123 to PR-132), the regional director of the Autoridad de Carreteras y Transportación stated that the PR-132-to-PR-500 segment under construction (Phase III) had sustained damages from the quakes.

The segment connecting, which was already running two years behind schedule prior to the earthquakes and which was due for completion by September 2020, would now have a completion date based on the results of an evaluation "at greater depth" of the damages caused by the earthquake.