Rail off
Definition 1 of 1
Pro Tip 1/3Safety Measures
Used to indicate setting up safety boundaries in hazardous zones. 
They had to rail off the damaged bridge to prevent accidents.
Pro Tip 2/3Restricted Access
Implies limited access to a specific area for protection or privacy. 
The celebrity's house was railed off by the security team.
Pro Tip 3/3Temporary Barrier
Often refers to a temporary setup that can be removed later. 
After the festival, they removed the rails that had been railed off.