OK, if birth is imminent, you are premature or there is a medical condition which indicates straight to labour and delivery, call an ambulance, but dont do it if your waters haven't broken and contractions are every 2 hours, or lets just evade the congestion/car parking/public tranpsort fee, lets just call the ambulance. Suppose, hell mend, this 24 year old female dies, if she already hasn't, she could have stood a better chance of survival had the ice cream van not being playing maternitaxi to probably another teen in the first stage of labour and cant handle the pain, cynical me!