I don't know what it is but...
As you get older you think of things like this.
At least I do.
For security professionals, vehicles have become real possible threats. Vans in particular. Used, to deliver danger in the form of a terrorist attack. Right to the front door, right into the bowels of buildings, to create the most devastation.
Here are some deterence methods now being employed to protect vital Government Buildings and Monuments.
Bollards and Barriers
These devices are designed to keep vehicles away from the perimeter surrounding a structure. They include concrete posts and planters and are used as decorative barricades called Jersey barriers. I've even seen big large balls, placed strategically around a Banks doors. These are good to keep unwanted vehicles out of restricted areas but are not good, used as gates. to fully remote computer high tech operated, hydraulic metal posts and plates that automatically rise from the ground, in little silos. Impossible to penetrate.
Bollards come in several varieties:
Fixed - Cost effective, visually more pleasing, (planters with built in Bollards) protects perimeters of large areas. (Airports, etc.)
Removable - As the name suggests. May not pass standards. Since they are more light weight.
Retractable or Automatic - I saw these at the White house once. I was impressed. Big shiny stainless steel bars, pop up out of the ground and retract back in.
Manual Retractable or Semi Automatic - Used for less common areas and are less cost effective. Devices lock into place and are operated manually. This method is usually used along with other devices.
Crash Gates - As the name implies. A barriers that is hard for a car to crash through.
Wedge Barriers - Steel plate or rods, rise from the road at a 45 degree angle which deflects the intruding vehicles force when crashed into it.
Drop Arm - Much like a railway crossing. Allows easy access and can block oncoming traffic. Altered somewhat to throw out a lasso which grabs the vehicle and destroys it's front end, immobilizing it.
Portable - Speedy, easily installed. Mobile and can be installed on existing roadways. Highway improvement projects use barrels full of sand.
These are the types of Bollards and Barriers used. Becoming more popular since 911. Let's hope that's enough.
In my eyes... the targets are endless. But it helps, wouldn't you agree?
Info: A handbook of Best Practices
Cities and Cars. Edited by Roger L. Kemp.