Integrating light rail with our regional rail system?

The following is from an email asking about the reasoning behind not integrating light rail with our regional rail system:

After reading Brent Efford's RTSA Presentation about tram-trains I'm disappointed that your group is promoting a hypothetical light rail system that is disconnected and has a track gauge incompatible with our regional rail network. If this idea spreads it will screw our city over and we will never have a fully integrated regional rail system. The only reasoning provided by you is that it's cheaper (which certainly appeases typical NZ short-term thinkers) and the vague claim that the Johnsonville line has too many riders for a single track light railway - can you please elaborate on why you believe that is the case? I have a hard time believing this would be a problem without a solution.

As seen with our recent bus network, having to transfer between services is a major deterrent to using public transport. If one could get a single comfortable ride from Waikanae or even Masterton to the Hospital or Airport then I think we could expect PT use to absolutely skyrocket, which is what we should be aiming for in the current climate (pun intended). A disconnected service will not provide the region much more utility than our current bus system, apart from a more comfortable ride. The tram-train solution shines with logical brilliance, and seems to be the most intelligent option for the Wellington region in the long-term. I urge you as a group to re-evaluate the plans your are putting forward to the public.

FIT does not see Brent Efford’s ideas as feasible for Wellington.

Some tram-train systems have been very successful, but many cities have abandoned the idea. Twenty seven years after the Karlsruhe system opened, only about 30 tram-train systems exist, and fewer still are comparable with Wellington.

Karlsruhe model: street running of Stadtbahn in Heilbronn / Wikimedia Commons CC BY-SA

Karlsruhe model: street running of Stadtbahn in Heilbronn / Wikimedia Commons CC BY-SA

Nobody likes transfers, but hubs are essential to a quality public transport system, and quality systems are very popular. Other approaches require excessive route duplication, which explains many of Wellington’s bus problems. The best approach is properly designed hubs, as in Auckland and Christchurch, rapid transit to offset the transfer delays, and reliable connections. World-leading public transport systems, such as den Haag, Vancouver, Freiburg and Zurich, all use hubs.

A principal feature of cities suitable for tram-trains is walking distance from the terminus to the city: 1900m to the city centre in Karlsruhe, Zwickau 1800m and Saarbruken 800m. In Wellington the centre-of-the-centre walking distance is only about 550m, to Brandon St, and many passengers walk much further. A secondary city feature is residential densities, low in Wellington (but likely to increase). 

The only quantifiable advantage of tram-trains is through-running, allowing some passengers to avoid a change at the Railway Station. In Wellington, universal through-running is impractical, because it would overload the street-running tracks. This means that the through-running objective cannot be met in full. FIT has not been able to find any examples of running so many lines through the city centre onto a single track, so Wellington would be the pioneer. The alternative best-practice hub approach achieves delays of rarely over five minutes and often under two, routinely accepted in many cities.

Tram-train costs in Wellington would be substantial but have never been quantified, and there has never been any study of how—or if—KiwiRail would accommodate them:

  • The maximum practical length for a light rail vehicle running on city streets is around 70m, compared with 129m for a six-car Matangi and 172m for a maximum-length eight-car Matangi. Hence tram-trains on KiwiRail tracks would drastically reduce track capacity, when the objective is to attract many more passengers.

  • Auckland has chosen standard gauge (1435 mm), and will develop the standards needed. If Wellington makes the same choice, there will be cost savings from both common standards and repeat orders.

  • KiwiRail’s 1067 mm track gauge is very rare for light rail. Most modern light rail vehicles are designed for either standard or metre gauges. The wheels are either inside or outside a standard bogie-frame, leaving no space for the extra 67 mm. One estimate of a bogie re-design is $50 million. Vehicles for 1067 mm gauge would probably come from CAF, and single-suppliers are not cheap.

The tram-train studies claimed by Wellington proponents are in fact studies of converting the Johnsonville Line to light rail; it would be far simpler. FIT would like to see a light rail extension to Johnsonville, but has not proposed anything more than a study, because of multiple uncertainties. One of them is vehicle-width in the Johnsonville tunnels.

The Johnsonville line now has a 15 minute peak-hour timetable, using four-car Matangis. Converting to light rail would reduce present-day capacity slightly, with substantially fewer passengers seated. A more serious problem would be a permanent limit on vehicle length. Future capacity-increases would only be possible by increasing frequency. Capacity could be roughly doubled, but no more, and might not be enough.

These comments notwithstanding, there is nothing to stop a supplier responding to a Wellington light rail request for proposals by submitting a proposal for a tram-train system. If tram-train is the best option, it will emerge as the winning proposal.