I think it's interesting that one of the women in this article mentioned hypnobirthing, which I think can keep a woman calmer than medical staff feel she "ought" to be during late stage labour.
When I had my second son, I knew I was in advanced labour when I rang the hospital from home, as the contractions were every 5 minutes (waters had already broken), but I was told that I couldn't be that far on as I could still speak during the contractions (hadn't even practiced hypnobirthing for this one!). We went to the hospital anyway and my husband had to abandon the car outside the hospital front doors! I gave birth as soon as we got into our delivery room.
For my third birth, I practiced hypnobirthing for the first time and it kept me very relaxed. We arrived at hospital and were not allocated a midwife as they were all busy and they didn't believe I was close. We were left in a delivery room and shortly afterwards my husband had to go and "steal" a midwife from another woman as I was about to give birth.
Highly recommend hypnobirthing by the way - had naively assumed it was some weird hippy rubbish previously, but actually it is all quite sensible and evidence-based. Wish I'd done it for all 3 babies. Didn't go to expensive classes, just had a great book.