From OpenStreetMap Wiki
|barrier = full-height_turnstile|
|A full-height turnstile|
|Used on these elements|
|Tools for this tag|
A, also called HEET-turnstile (High Entrance/Exit Turnstile), like the ones to access security areas. Note the mix of hyphen and underscore in the value.
How to Map
Simply add the tag barrier=full-height_turnstile to a node where the turnstile is.
You should also add further tags to more fully specify what kinds of traffic have reasonably unhindered access using access=*.