I took a couple of minutes to observe this a few days ago @ 5pm on a weekday.
There is enforcement but it is cyclical. It is this police SUV that comes around blaring its horns - everyone moves off immediately at that point. However, it doesn't come around again for some time so in the interval, there are always taxis waiting. The guys in vests (they are a constant presence) with walkie talkies walking up and down do not appear to care - they do not instruct taxis to move and pickups happen right in front of them.

Taxi drivers always helpful with the one-way turnstiles in case you don't know how to work them.