It's 12 hours online AND driving. Meaning if you're stopped between calls, that stoppage is not counted towards "online time", even though you were online. It typically takes me 13-15 hrs of actual time to hit the 12 hr "driving" cap if it's busy. If it's not busy it's basically impossible to hit it.Is it 12 hours total driving only or 12 hours online?
You can get the actual numbers any time by going to account->driving time in app.