UPDATE: The President completed his visit at about 6:30 PM. Roads are back to normal.
From the Town of Palm Beach:
CHANGES IN TRAFFIC PATTERNS BEGINNING FRIDAY, MARCH 8, 2019 NO LATER THAN 5AM
The process of establishing checkpoints and road closures in and around Mar-A-Lago will begin Friday, March 8, 2019, no later than 5AM. Expect traffic delays and road closures in this area thru Sunday, March 10, 2019. Motorists are encouraged to seek alternate routes.
It is recommended that all household staff, landscaper maintenance companies, pool companies, etc. adjust their schedules accordingly so as not to spend an unnecessary amount of time in traffic due to the closure.
Read More (Town of Palm Beach)

The President is expected to host his first major fundraiser of 2019 at Mar-a-Lago on Sunday, according to published reports.
Mar-a-Lago visits may increase this month.
The President tweeted in February that he hopes to finalize a trade agreement with Chinese President Xi Jinping at Mar-a-Lago sometime in March.