Tunnel vision can make a difference


High-tech camera’s, are having a positive impact in making the Homer Tunnel on State highway 94 to Milford Sound even safer for road users.

Tunnel vision can make a difference

Several sophisticated cameras keep a lens over traffic movements inside and around the single lane tunnel, as well as monitoring nearby rock fall sites.

The cameras are managed from New Zealand’s only alpine road traffic control centre perched 900 metres above sea level, at the eastern entrance to the Homer Tunnel. All the camera images are monitored by eagle eyed operators at the control centre, who can remotely rotate the cameras and zoom in very close to identify potential issues.

Transport Agency Southland Network Operations Manager Peter Robinson, says the control rooms main role is managing fire and traffic risks inside and close by the tunnel. The cameras are invaluable for detecting buses with heating problems before they enter the tunnel and potentially catch fire.

Peter said often these buses on the long steep slog from Milford Sound to the western tunnel entrance, stop at the bottom of the last climb before the tunnel to fill their water reservoirs, before continuing the onwards and upwards grind. 

“The tunnel control operators can zoom in on these buses and manually red light them, so they stay put until our road contractor’s staff arrives to check that it’s safe to let them continue through the tunnel.”

In an emergency, tunnel traffic control centre staff can close the tunnel immediately to all traffic, if a risky vehicle is identified. They also shut the tunnel to general traffic, so that dangerous goods like fuel can be transported to and from Milford Sound, without putting other road users at risk.

Peter said recorded video footage is assessed each day by the control centre staff and all incidents recorded are logged

“We follow up with company’s whose buses are seen running red lights at the tunnel.”

The traffic control centres operates from 11am to 5:30-6:00pm in summer when risk of fire is highest.

With the nearest electricity supply over 100km away at Te Anau the whole operation depends on generators, batteries or solar panels.  Because the generators operate in a national park they cannot run before 6am and must be switched off by 8pm.  Batteries are charged during the day to run things at night.

Peter said the traffic light infrastructure is designed to be easily relocated for summer and winter operations at the tunnel. 

“All tunnel equipment is built to handle the weather extremes in this area. These range from 400km/h plus wind speeds generated by avalanche, ice and snow conditions, to summer heat of 30 degrees. Everything is made to be replaced relatively quickly if it’s destroyed or damaged.”

Nature in this part of the world can be a menace in unexpected ways, with an example being the mice and Kea that mount attacks on gear at the tunnel. The razor sharp beaks of the Kea inflict a surprising amount of costly damage to plant and equipment.