Frequently it's a physical barrier that springs back up when hit and does not prevent cars from parking. Here's an example: http://nyc.streetsblog.org/wp-conten

Frequently it's a physical barrier that springs back up when hit and does not prevent cars from parking. Here's an example: http://nyc.streetsblog.org/wp-content/uploads/2018/12/grand-blocked-46.jpg http://nyc.streetsblog.org/wp-content/uploads/2018/12/grand-...