Zombie Fighting Tactics - How to Ambush Zombies

Zombies aren't the most aware of creatures.  They'll walk into almost any trap you set.  It should be relatively easy to ambush them right?  Not necessarily.  Since zombies travel in groups, sometimes very large groups, you have to choose your ambush site carefully so that you can get the Zombies, but they can't get you!

Zombies on this Raised Roadway Can't Get You Without Tumbling Off of the Roadway

One key thing to do is try to attack Zombies when they are in a position that they would hurt themselves in any attempt to get at you.  For example, if you can find a position to shoot zombies as they walk across a raised highway,  the Zombies will naturally walk towards you and off of the overpass in an attempt to get at you.