After arriving in New York JFK from LOT Polish, I nearly missed my connection to Los Angeles due to ongoing airport construction and very poorly-marked signage. If using the JFK AirTrain to connect between terminals, allow extra time.
Allow Extra Time For Connections Due To Airport Construction At JFK
I landed in Terminal 7 and my connection was in Terminal 5. The terminals are right next door to each other and I could have easily walked over, but the pedestrian path is blocked.
Instead, I took the AirTrain (the train that connects all the terminals as well as the airport to the Jamaica subway station). But at first, I could not decipher the departure board. The next two trains that were coming were going to parking structures, but there was no mention of any terminal stops (beyond Terminal 8).
Only one of the two tracks was open. Unlike in the past, there was no one there wearing a vest to help guide travelers.
So I went downstairs and tried to cut through the parking lot to get to the TWA Hotel and T5, but I could not safely pass, so I went back upstairs.
Finally, a train showed on the departure board that would loop from Terminal 8 to Terminal 1, then Terminal 4, and then Terminal 5. Yes, I had to go around the whole loop since trains are currently only running in one direction.
Long story short, it took three times as long as I thought. Since I only had an hour to connect, I almost missed my flight when I hit (normal but heavy) security lines in T5.
So very simply, allow extra time when connecting at JFK, because the airport is a mess and it may take extra time to connect. JFK will be beautiful when construction is complete, but is not very travel-friendly right now.