Why does the Terrace Tunnel need to be upgraded?

The Terrace Tunnel needs to be upgraded to bring it in line with today’s standards and to extend it working/functional/operating life.

What does the project include?

The upgrade will involve upgrading the fire, lighting, ventilation, drainage and earthquake safety systems in the Terrace Tunnel. This will include replacing the tunnel’s current ceiling and wall panels, jet fans, lighting and fire sprinklers, installing a new deluge system to combat any potential tunnel fires and establishing new control buildings to the north and south of the tunnel.

What are the benefits of the work?

The upgrade will extend the tunnel’s operating life and enhance tunnel safety, ensuring this vital link is maintained for Wellington’s transport network.

When is work going to start?

Work is scheduled to begin on 6 December 2010.

How much is the work going to cost?

The work is expected to cost roughly $50m.

When is the work going to be done?

To avoid traffic disruption the bulk of the work will be done overnight. This means the tunnel will be closed from 8pm until 6am Sundays to Thursdays.

Will the tunnel always be closed at 8pm between Sundays and Thursdays?

There will be occasions when the tunnel isn’t closed due to events being held in the city or for other reasons that might affect traffic flow in to or out of the city. If this happens we would close the tunnel later or potentially not close the tunnel overnight if the situation required us to keep the road open.

How will I know when the tunnel is closed?

You can check our website, listen to the radio or check Monday’s Dominion Post for dates and times of closures. You can also call the Wellington Tunnels Alliance on 0508 WTA 444 (0508 982 444). We will do everything we can to make sure the public is aware the Terrace Tunnel will be closed overnight and know what the alternative routes are.

What impact will there be to daytime traffic?

The impact to daytime traffic is expected to be limited. The speed limit through the Terrace Tunnel will be lowered to 60km/h for the duration of the project as the lanes will be narrower through the tunnel and the tunnel will be darker. This will have no effect on peak traffic as speeds are normally much slower at these times.

Why is the speed limit being lowered in the Tunnel?

In order to make room for the work to be done at the side of the road, the project team is going to make the road lanes narrower. For safety reasons, this means the speed limit needs to be lowered. It will be returned to its usual 80km/h when the project is completed.

Will work be carried out over the Christmas holiday period?

The final tunnel closure before Christmas will be on the night of 23 December. The tunnel closures will resume on 5 January. There may be small amounts of other work going on during the Christmas period but these will not require the Tunnel to be closed.  

How noisy is the work going to be?

There will be some noise involved with the work as old equipment needs to be removed and new equipment installed. Every effort is being made to ensure that construction noise is kept to a minimum. This includes doing the noisiest work in the early evening so nearby residents are not overly inconvenienced. The team is also considering other ways to limit the amount of noise that is made.

What happens to traffic when the tunnel is closed at night?

Traffic will be diverted on to other roads to reconnect with the state highway between 8pm and 6am. The diversions are - northbound traffic will be diverted to the Everton Terrace motorway on ramp via Willis Street, Ghuznee St and The Terrace. Southbound traffic will be diverted off the motorway at the Terrace off ramp to re-join the usual route at Vivian Street.

Will traffic increase on other roads as a result of the Terrace Tunnel upgrade?

Some preliminary work to see how other roads will be affected by the Terrace Tunnel closures and worked with Wellington City Council to see how to best manage this. As a result we will keep a close eye on how traffic flows change and, if necessary, make changes to traffic signals to limit delays or consider other options to improve travel.

Traffic may increase on local roads at night when the Terrace Tunnel is closed.

Will any other roads be affected by the work?

Occasionally there will be work on The Terrace relating to services (ie water, power, telecommunications cables), however, the impact will be minimal and one lane of traffic at least will be kept available at all times when this happens.

Could the work be done another way?

The NZ Transport Agency considered closing the tunnel completely over the Christmas period but decided this was not the best way to manage the work due to the impact it would have on daytime traffic, even during the quieter Christmas period.

What plans are in place in case work in the tunnel is not completed by 6am in the morning and the tunnel can not open on time?

The work programme has been planned very carefully to avoid this happening however, in the unlikely event the tunnel can not open at 6am in the morning contingency plans will be put in place and alternate routes will be advertised on roadside signs, on the radio and on the NZ Transport Agency website.