Well the container idea was originally thought up for urban scenarios that have blacktop to contend with. Just anchor the containers into the road surface and add some sandbags/jersey barriers inside the container for ballistic protection.
The original concept was to use containers following a major road to secure the ports along the Brooklyn side of MY Bay. Lay a line of them down the Gowannus Expressway to secure the dock areas to the east. The players were concerned with the idea of having to secure the many buildings that form the perimeter now.
Or even just to help establish a base for patrols to work a particular section of highway. Set up a few of them spread out over a 4 lane highway and it can ensure that road is kept clear. Like down the Long Island Expressway.
