In Hazard or Trial zones, enemy groups tend to be much larger in number and closer together than City Zones. The way I see it, Trial zones usually contain Task Forces, Strike Forces, or Trials... Hazard zones usually have a GM lurking about somewhere from time to time. These zones used to require Security/Threat level clearance, but that is no longer true.
I've tried doing some research, and I can't seem to find a solid answer to this question: What's the difference between hazard zones and trial zones? I know that both are a little harder to survive in than normal zones, and they may or may not have special enemies/spawns within them. Beyond that though, I can't tell the difference between the two of them. Can anyone help me out with this?