July 18, 2011
Page 26 Book 5: The War Diaries
Warning: Traffic collisions may impair your travel time. Also your life.
This is by no means a recent or fantasy tactic as it happens, it was often the case in medieval warfare that one side would build ditches and such that were insurmountable by horses and horse-drawn carriages in order to create an impassable point that created casualties and sitting ducks. Once the trench is filled with gore, it also serves as an environmental barrier, since its hard to move past it compared to the surrounding area.
That said, probably a new tactic of digging them underground and then collapsing their ceilings with explosives…