The New Zealand Transport Agency has been demonstrating the safety features of the state-of-the-art tunnel in central Auckland.
Those features include a sprinkler system capable of ejecting 250 tonnes of water an hour.
Exit doors every 50 metres would lead people in the tunnel to a separate pressurised passage and jet fans would remove smoke and gasses from the tunnel.
Closed circuit television cameras enable the 450 metre tunnel to be monitored constantly.
In an emergency a public address system would cut into any radio station motorists in the tunnel were listening to.
All mobile phone networks have reception in the tunnel.
Two of the tunnel's three lanes, which take northbound traffic to the city's harbour bridge, are due to open on Monday.