Questions about the proposed route, Answered!

The Kilbirnie Rongotai Lyall Bay Resident Association approached FIT with a number of questions about the proposed light rail route. As their residents will be impacted / benefited they sought answers to the following questions about the proposal’s impact in the Eastern Suburbs (Kilbirnie, Rongotai, Lyall Bay, Miramar, Strathmore, Seatoun, Mapuia).

Proposed light rail route from the airport to the railway station

Proposed light rail route from the airport to the railway station


Q1 What numbers of current bus users do you expect to use Light Rail to travel into the CBD and will this impact our current bus service?

A1 About half on golden mile routes, and yes: see A7.

Many passengers will connect to light rail at a hub, often saving more time on a faster trip than is lost at the hub.

In Kilbirnie, light rail will connect with buses at a hub at the south end of Bay Rd, or in Miramar at Miramar Av near Hobart St.

Q2 What numbers of private vehicles do you expect Light Rail to remove from the roads?

If possible please identify numbers of vehicles going to Airport versus other destinations and the source of your data.

A2 Much will depend on design details. The faster light rail is the more effective it will be, because most transport users choose whatever is quickest and most reliable. We have an ambitious target, an average speed of 30 km/hr including all stops. The more closely this can be achieved, or exceeded, the more effective light rail will be.

Light rail would be more effective if ‘four lanes to the planes’ (including two new road tunnels) was cancelled. Building more roads simply locks in more traffic and greater congestion. A much more effective approach is improved alternatives, especially fast public transport and cycle lanes.

A principal benefit of light rail will be making the inner-city buses much more effective, by relieving a badly overloaded golden mile.

Q3 How will your light rail proposal reduce congestion on weekends when people in the Eastern Suburbs are not going to the CBD (noting congestion is worse on the weekends)?

A3 Good public transport should be equally effective at weekends, and greater revenue (as patronage rises) will allow more frequent weekend services and longer operating hours.

FIT envisages a minimum 10 minute service, from at least 7 am to 7 pm, every day, with less frequent evening and early-morning service. Light rail should run early enough to connect with the first buses and late enough for the last; say 18 hours a day.

Some cities encourage weekend usage by providing additional benefits for subscribers to monthly or annual travel passes, such as free travel for family members on weekends.

We have proposed a stop at the Rongotai Sports Centre.

Q4 How many members of FIT that were involved in this design live along the proposed line and commute daily to work in the CBD?

A4 One (of 7) of us lives on the proposed line, but all have experience of congested commuting. Most of us have lived in or at least visited cities having the kind of system proposed.

Q5 How will people that live more than 200 meters from the Light Rail Stops, e.g. in Lyall Bay, Kilbirnie Heights, on Miramar Hills and north Miramar access the Light Rail?

A5 A typical ‘walking catchment’ for light rail is a one kilometre corridor straddling the line, or say 600–800 metres for a bus line. Data from other cities consistently shows that people willingly trade a longer walk for a faster trip.

Ideally bus lines should cross the light rail line at a hub, but in Wellington a more complex layout is needed. For example, lines 12 and 24 might be joined in a Miramar hub, both timed to meet light rail as well as possible. Similarly, the existing line 23 could connect to light rail at Kilbirnie.

Cycling, or electric scooters, are likely supplements to walking. Better facilities for people transferring, and for storing cycles and scooters, are also needed at hubs and railway stations.

Q6 Have FIT undertaken a formal traffic impact assessment?

A6 FIT expects that officials will carry this out and report the results, before any final decisions are made.

Q7 What advantages are there over a properly functioning bus service?

A7 The question is the wrong way round: in Wellington, a properly functioning bus service needs light rail. Central Wellington has only three north-south streets for all purposes, and badly needs a new, high-capacity public transport route. Bus Rapid Transit on a 2 lane corridor provides about half the people-moving capacity of a double-track light rail line. A subsequent upgrade to light rail for increased capacity would be very disruptive.

Light rail is probably about ten years away, but there is no need for bus route improvements to wait as long as that.

Bus reliability improvements will hopefully begin very soon. Bus lanes can be extended and much-improved, but are not always practical. Other measures include traffic signal priority, junction layout improvements, measures to keep buses out of traffic queues, stop improvements and fewer stops. One quick and easy improvement would be to require cars to yield to buses signalling to leave a bus stop.

Light rail, with well designed transfer hubs, will roughly halve bus numbers on the golden mile, to the point where buses can keep to time and make more consistently reliable connections at hubs. All public transport in the WCC area will function more effectively.

Another light rail advantage kicks in as ridership grows. If light rail takes half of golden mile ridership on opening day, and then takes nearly all inner-city ridership growth on a much-improved system, it will quickly reach 3500 passengers an hour. It will then be cheaper than buses, because the operating-cost savings are enough to cover the capital charges.

Q8 What road works and elevations are required in Kilbirnie / Cobham Drive?

A8 At the busiest intersections, grade separation may be required (such as a rail overbridge). At less busy intersections, light rail priority is provided (other traffic is automatically stopped for light rail vehicles), in the form of traffic lights and in some instances barrier arms.

FIT expects that officers will carry out detailed modelling of every intersection along the route to establish the most appropriate options with respect to elevated or at-grade crossings. Other cities have found to their cost that if you get it wrong, it's really difficult, and sometimes impossible, to fix. Build it right the first time.

Q9 Will the light rail require a subsidy to operate?

A9 It depends. The single largest operating cost component is the driver's pay. In cities with human drivers, light rail services typically require about 1/3 the operating subsidy as a bus service. This goes back to the answer to Q7, that above about 3500 passengers / hour, light rail is cheaper overall than buses. Cities with self-driving (autonomous) light rail vehicles typically require no operating subsidy; the farebox is sufficient. This gives local authorities greater flexibility to introduce pricing policies that encourage public transport use, such as lower fares, at less cost.

Once the line opens, Wellington may wish to consider introducing a congestion charge for cars entering the city centre during certain hours, and using the revenue raised to subsidise public transport. In a polluter pays model, the people causing congestion meet the cost of relieving it.

Q10 How do you propose to manage intersections e.g. at Rongotai and Coutts St so the light rail does not have to stop given there are cycleways, cars and pedestrians crossing the lines?

A10 See A8 above. It becomes much easier when the light rail computer talks to the traffic signals computer, for example, ‘priority in 60 seconds,’ followed by ‘priority in five seconds’ about a minute later. The traffic-signal computer can then plan to give priority for light rail with minimum delays to all. A typical light rail phase is only about 10-15 seconds.

Q11 What is the noise level of the light rail in Decibels and does this peak during braking?

A11 One suitable vehicle (Siemens Avenio) has a maximum outside noise level of 46 dB(A) when stationary, and 70 dB(A) inside at 60 km/hr. No external figure is given, but ‘quieter than a bus’ would be reasonable. Most braking is regenerative, which makes very little difference.

For one example, see the Acoustic Characteristics section of this PDF.

Q12 Where will the light rail cars be stored?

A12 FIT has two sites in mind, one of them in the eastern suburbs, but they need to be confirmed by professional studies before they are made public. A likely layout is light rail at or below ground level, with development above: residential or commercial.

Q13 What is the likelihood that a vehicle accident on the line could block the light rail service?

A13 Crash and breakdown rates are low but not fully avoidable. Cyclists are at some risk, motor vehicle drivers at perhaps greater risk, especially when turning right across rail tracks, light rail passengers at very low risk. Countermeasures include design for good visibility, traffic signals at all intersections, and detailed planning to restart services as soon as possible after a crash or breakdown.