Actually, this was more helpful than i thought. I knew it was in that area, but now i know exactly where to change it, all i need now is how.
(I'm sorry if my English doesn't translate well)

Change them into Walkers, Then when they leave the trigger, go back.

I've been trying this for quite a while and nothing really seems to work, so how do i make it when zombies hit a trigger their speed goes down or a number controlling speed goes down?
Thanks again for the 2 millionth time. 

Hello again everyone and thanks for the help with my latest venture  luckily that was solved, now onto some stuff I just can't find.
How in the hell does the semtex stick to the zombies? I have the waw sticky and it doesn't seem to work the same (unless i'm just hallucin...

Ohhh myyyy gooood, I was just complaining about this to a friend when i found this, you sir are a god! Just kill me now 'cus it ain't gonna get any better than this.

Adding holes in the walls seems to help the player gameplay-wise while looking pretty good and adding a nice feel to the map.