I gave birth on the side of the road (luckily in an ambulance) on the way to that very same hospital! It's a bloody long way by road from Canterbury to Ashford, even when the roads are clear.
Sadly they closed the birth centre at Canterbury so you have the choice of 2 hospitals that are many miles away, there have been a few born on the side of the road recently :).
My midwife at the time told me I'd have plenty of time to get to the hospital from home, turns out she was very very wrong!