"When we're trying to focus on the incident and get there as fast as we can safely, it makes the job a lot more stressful and unpredictable. In the event of a fire or medical emergency, a delay of even a couple of minutes makes a huge difference to the outcome."
Mr Moreland said crews were delayed about 50 per cent of the time when they were on their way to callouts - delays which could mean life or death for the people involved.
The fire service was being called to more medical emergencies and the issue of motorists not giving way also arose when the Greerton fire trucks were leaving the Maleme St station.
Mr Moreland said a two-minute delay could be the difference between a person succumbing to smoke inhalation in a fire or being rescued.
St John Western Bay of Plenty territory manager Ross Clarke said most motorists did the right thing but some were unpredictable once they realised an ambulance was trying to pass them, and did "all manner of strange things".
That included some drivers stopping in the right lane and expecting the ambulance to go around them, he said.
Mount Maunganui Fire Service station officer Neil Brown said the issue was a major concern. "It's a re-occurring problem in at least one in two to three callouts. I don't know whether it's ignorance and people really don't know what to do, but some people are being a little bit selfish when they don't pull over and leave a sufficient gap for us to get through.".
Mr Brown said it was also common to see people waiting to enter the nearby intersection queuing up in front of the fire station during peak heavy congestion, he said.
Tauranga Fire Senior Station Officer Kevin Cowper said if motorists failed to give way to emergency services it was often because they were oblivious to what was behind them.
Mr Cowper said some drivers were unpredictable.
"For those who deliberately don't pull over or try to beat the fire truck they should think about the fact that we might be on our way to an emergency involving their property or someone they know.
"In the event of a building fire once the fire takes hold it grows exponentially ... even a delay of a couple of minutes makes a huge difference," he said.
Head of Western Bay road policing Senior Sergeant Ian Campion said drivers should think about how they would like other motorists to respond if the emergency involved their family member.