With DD1 I went straight in since my waters broke first.
Ended up with he option of going or staying. Stayed coz I was a bi freaked about it all & lived an hour away.

DD2 - contractions were still 30 mins apart, but the pain was unbearable. I wasn't gonna leave home til they were 5 minutes apart. Well as soon as I got up they were 5 minutes apart. Got to the hossy (an hour away) at around 7cm dialated.

DS - Was gonna hang at home even after waters broke til necessary, but had mecconium in fluids, so went in to be checked out.
Had to be monitored & ended up having him only 2 hours later.

I think the rule if your not sure is get checked if waters have broken, contractions around 5 minutes apart, or if your worried about something.
Its really whenever you feel comfortable depending on how far you have to travel.