A three tiered public transport network

Posted on February 21, 2012 by


Recently I posted about simplifying the bus network, and focusing attention and investment on a core network of routes which consist of pendulum style routes through the CBD, and cross-city routes which do not pass through the CBD, but which cross the pendulum routes at key suburban interchanges. This was followed up on with an excellent post from reader JJ Barnes, which reaffirmed the need to focus on a core bus network with high service frequencies, suburban interchanges, priority measures, and increased stop spacing. This was illustrated with a concept of six core bus routes, four pendulum and 2 ring, around which the remainder of the bus network would operate and connect into.

I think that this simple concept of developing a core network of bus routes, readily achievable with comparatively few resources, is a great starter for ten. However, what happens beyond that? What kind of major investment in public transport infrastructure in Christchurch would build upon those sort of solid foundations and pave the way for a truly world-class transport system for the city? I see that core bus network as just a first step towards a better system.

We know the final draft Central City Plan proposes a commuter rail/light rail/tram-train/rapid transit  (take your pick) network, part of which utilises the existing rail corridors. So if we take the basic network, ignore the rail connotations and simply call it a “rapid transit” network, how does it fit into the wider public transport system?

Taking the rail schematic provided in the final Plan, and laying down key bus routes on top of it (i.e. existing bus routes that are a candidate for being a part of a core network of bus routes) you start to get an idea of how such a system might operate. Like I said, ignore the rail designations for now and just think of it as rapid transit. Key interchanges would be the CBD, Riccarton, University, Hornby, Linwood and Papanui, with other minor interchanges located at suburban centres. This is just an example I thought I would try out, utilising existing bus routes I think could be developed into core routes. Of course, there is plenty of scope for change, especially with routes like the Orbiter, Metrostar and Comet, but for now this will do to illustrate a basic network for the city.

So essentially you would have three levels of service: Rapid transit – which largely has its own right of way, has high service frequency, large capacity, is served by major suburban interchanges at key nodes, serves regional centres, and along which intensification and commercial zones are focused; Core bus – bus routes with high service frequency, higher capacity buses, links key nodes along major arterial roads, features bus priority, and offers direct services; Local bus – less intense routes, 30 min or less frequencies, links into core bus and rapid transit networks at interchanges, smaller capacity buses.

Auckland has a similar method of catagorising public transport routes, designating a “Rapid Transit Network” (RTN) and “Quality Transit Network” (QTN). This can be seen in the map below (RTN = red; QTN = green) and shows well the interaction between the two, and the roles they play in the overall transport network. The RTN forms the backbone of the network, while the QTN is made up of bus routes with high frequencies that run along major arterials.

The dotted lines represent future RTNs, and I think while the priority for Christchurch should be to establish something similar to the basic  rapid transit network outlined in the draft City Plan, securing corridors for future expansions to the network should also be a priority (for example, continuing the New Brighton line further through the north-east?).

Suburban interchanges I envision being of two different types – lets just call them “primary” and “secondary”. Primary interchanges would be at major nodes served by the rapid transit network. If possible, they would be a fully integrated facility serving buses and the rapid transit mode (for example, rail). This might not always be possible, so good, sheltered links between different parts will be essential (for example, a rail station next to the railway line and a bus station near the main road that have development separating them). Primary interchanges would have large sheltered waiting areas, space for shops, perhaps an info counter, lockers, bicycle lock ups and so on. They would be a public space.

Secondary interchanges would be located at suburban centres where core and local bus routes meet. These would offer a high quality facility, with bicycle lock up, lockers, a large waiting area, perhaps a cafe, but I imagine would be smaller in scale than the primary interchanges. Something similar to the current Central Station bus interchange in the CBD comes to mind, though possibly a bit smaller.

Then there would be regional centre interchanges. These would be located in places like Rangiora, Kaiapoi, Rolleston and Lyttleton (possibly Prebbleton if the spur line became part of plans?). They would be similar to primary interchanges, but given the distance from the city would also incorporate features like park and ride, and kiss and ride. They would also be the centre of their areas transport system, with local bus services all terminating there. Lyttelton would be slightly unique in that it would be an interchange between rapid transit (rail), local buses, and ferry services.

In terms of staging, my way of thinking is that the core bus network should begin to be implemented first as a “quick win”, followed by the rolling out of the rapid transit network (dare I say the routes along existing rail lines should be first?). In terms off the rapid transit network itself, how I think it could/should be rolled out and staged is another story altogether, which I will explore in a not-in-the-too-distant-future post.