Esso station Frankfurt airport
 

Tried to fill up my rental car before returning it to FRA yesterday as I normally do and found it impossible to get to the ESSO station due to the construction-related closure of the traffic circle and no umleitung signs. Didn't have time to play around with trying to find an alternate route.

Is the Esso station in fact still open and if so, how is it accessible? I came from the west (from Mainz direction). Could only make the exit right towards T2, not around the circle towards the station.

Yes this is a right pain at the moment. It is still open, but difficult to access.

If you come from the West (Wiesbaden, Mainz, Cologne) then you need to take the exit for T2 as you did, but as you can't go round the roundabout then follow the road towards the Terminal. At the first set of lights you need to be in the far left lane, and then you can actually make a U-Turn.
There are normally lots of people doing this, especially Taxi drivers!
Then follow the road back and go on the roundabout (left lane again), and then you can come off the roundabout for the Esso station.

There is also a Shell (?) on the Airport ring towards the west. But I have not been there, and it is more awkward to get to from the Autobahn.

Thanks, this is good information. Have they made that a legal u-turn for the time being, or just not ticketing anybody?

I'm not sure about the German road code but IIRC you can make a U-turn unless it's expressly prohibited by a sign. Autobahns and expressways are excluded from that where it is prohibited to make u-turns (In case you were wondering...).

I didn't see any sign prohibiting it. There are two lanes that turn left, the far left one you can do u-turns from, and when I done this just a few weeks ago most cars in this lane were doing this and about 50% of them were Taxis. So I wouldn't worry about it.

I would not know how to make a U-turn on the Autobahn :p

I bet that plenty of people (would) do it. It's the type of individual that think missing an exit is enough to justify such dangerous manoeuvres. Driving to the next exit is obviously to complicated for their tiny brains...