How FIT’s proposed light rail route has evolved

© Olena Ilienko / Adobe Stock

© Olena Ilienko / Adobe Stock

“When my information changes, I alter my conclusions. What do you do, sir?”

attributed to John Maynard Keynes

In developing its proposed route for light rail, FIT sought to meet several objectives:

  • maximize ridership

  • travel times compete with private car

  • form part of a rapid transit network

  • promote transit-oriented development

  • mitigate construction phase risk (eg business disruption)

Meeting these objectives requires a route with dedicated lanes for light rail and priority over other traffic, including grade separation at busy intersections. Those who wish to will find fault with whatever route is chosen. The challenge is to understand the trade-offs and choose the least compromised option.

Here are the principal options FIT considered, with reasons for our preferred option.

Q: Customhouse and Jervois Quays or the Golden Mile?

A: The Quays, for the following reasons.

There is room on the Golden Mile for light rail or buses, but not both. Where would the buses go?

A Golden Mile route would be close to more people, but the maximum speed would be 20 kph between Panama St and Taranaki St and 30 kph elsewhere. The Quays would allow 50 kph.

The construction phase along the Golden Mile would be expensive and disruptive. Many underground services would need to be relocated, especially in the Old Bank area. Shopping would be unpleasant. Many shops would be unable to sustain the lost business and close.

Light rail on the Quays and buses on the Golden Mile, cutting back to a maximum of about 50 bus/hr, and better priority, will provide a faster more balanced service.

Q: Taranaki Street or Kent and Cambridge Terraces?

A: Taranaki St, for the following reasons.

The intersection of Courtenay Place and Taranaki St offers a better layout for transfers between bus and light rail than the intersection of Courtenay Place and the Terraces.

Stops at the station, Frank Kitts Park and Te Aro Park put the whole Golden Mile within a short walk. People arriving at an Embassy Theatre stop from the south would have a longer walk.

Taranaki St offers more opportunities for medium density transit-oriented development than the Terraces.

FIT has been unable to find a good way to separate north-south light rail from east-west traffic at the Basin Reserve. The best option if a Terraces light rail route is preferred may be to elevate light rail from north of Courtenay Place (with an elevated stop) to south of the Basin, via Sussex St. Would this be consentable?

Whichever route light rail takes, FIT recommends relocating SH1 eastbound traffic from Vivian St to Karo Drive, with grade separation between light rail and SH1.

Q: Adelaide Road or Wallace and John Streets?

A: Adelaide Rd, for the following reasons.

Wallace St is narrow and running light rail there would mean closing it to through traffic. The John St section would be slow and getting across the intersection to the hospital would create all sorts of traffic hold-ups.

Adelaide Rd offers more opportunities for medium density transit-oriented development than Wallace St.

A tunnel through Mt Cook from Taranaki St to Adelaide Rd is a better route alighment than via either the Basin or John St.

Q: A Mt Albert tunnel or Constable St?

A: A Mt Albert tunnel, for the following reasons.

A Constable St route is only practical if you remove a row of houses; it's too narrow to accommodate light rail and other traffic.

Running light rail on Crawford Rd to Kilbirnie would be a major engineering challenge.

The section between Newtown and the Zoo offers more opportunities for medium density transit-oriented development than Constable St.

Q: Cobham Drive or an airport tunnel?

A: Cobham Drive, for the following reasons.

Miramar town centre is a high growth, high demand destination, ideal for a light rail stop.

The airport needs to be the last stop, because people with luggage take longer to get on and off. The schedule recovery time built into the timetable will readily accommodate this.

A route under the airport runway would need to split to serve both Miramar town centre and the airport. If the service runs every 10 minutes, this means Miramar and the airport would each get a service every 20 minutes. A direct route to Miramar and the airport delivers a better service to both destinations.

FIT understand that tunnelling under a working runway presents engineering challenges but is not a show-stopper.