Although selfish city drivers have been blamed for delaying ambulances, in fact patients calling 111 with relatively minor complaints are clogging up the system.
Last month the Herald reported that St John hadn't met target response times for "priority one" callouts in 2011, and St John blamed traffic congestion and bad road manners.
But ambulance officers say they're arriving at so-called emergencies with sirens blaring only to find someone with a minor ailment. They say the American-designed ProQA computer system is at fault, with too many calls being categorised as priority one.
Mark Quinn, chairman of the Ambulance Association, the union for ambulance drivers and paramedics in Manawatu, Whanganui and Horowhenua, agreed, saying operators with no medical training had a "rigid" list of triage questions.
But Alan Goudge, St John's national operations manager, said: "We will always err on the side of caution, and we must."
