Never noticed this before.

[bgets]

I discovered this on a flight from Grand Cayman to Atlanta. It was west of Everglades City so It's not the highway from Miami to Key West.
Bob G.

[tvieno]

I get something like that too in the Inside Passage up by Juneau, AK, US (PANJ), a thin line that runs north-south.

[andyjohnston]

It's what's left of the road to Atlantis.

[Firekitten]

Nah, its so you could land on early trans atlantic flights to refuel mid way... Not used much now due to bigger aircraft able to make the trip in one go, so they took up the runway leaving just the manmade island...


*grin*

[abrussell]

I have also experienced the line on the Inside Passage.
Bruce