Bus route planning – a challenging balancing act

The significant changes proposed to buses in central Auckland, plus my recent blog posts about how to improve bus flow through the city centre have highlighted to me what a challenging balancing act it must be for people whose job it is to improve the bus route network. That said, it’s also an incredibly important job, as Auckland’s current network has a huge number of inefficiencies, areas of duplication, areas of poor service, areas of overly long routes and so forth – all put together they produce a bus network map that does look like someone’s thrown spaghetti at a wall.

But this is not just an Auckland problem. Large parts of Sydney’s bus network are pretty difficult to make sense out of too:

That red route – the 473 – could hardly take a more indirect and slow route through Bardwell Park and Turrella if it tried. This is an example of a somewhat unbalanced approach to bus network planning, where all the emphasis is on getting the most people within a few minutes walk of the bus route – at the sacrifice of the speed and attractiveness of the route for people who have a choice between catching the bus and driving.

I suppose this is the most obvious balancing act when it comes to planning bus networks: the trade-off between speed and accessibility. You obviously want as many people to have access to the bus as possible, but at the same time you also obviously want to ensure the bus ride is not painfully slow. An example of something at the other end of the scale might be the Northern Express bus route in Auckland – it’s about as direct and fast as possible, but aside from around Sunnynook station, relatively few people live in close proximity to the route – meaning that there’s a reliance on park and ride stations, plus feeder buses.

A second trade-off is between network complexity and simplicity. How many different routes and route variations do you want? On the positive side of complexity is the ability to offer targeted products to what the demand might be: a slower and less direct route serving more places in the off-peak, express routes, peak direction only routes and so forth. But on the down side of that, the map and system can become very difficult to make sense out of – and public transport just becomes “too hard” to bother with. Not that I have much experience of it, but the bus network to Sydney’s Eastern Suburbs does seem to have a particularly high level of complexity to it:
You have a bunch of normal routes, some routes beginning with X, some routes highlighted as pre-pay only, some routes beginning with L. And even then within the “normal routes” you have a bunch of very similar routes (for example the 372, 373, 374, 376 and 377) that by in large follow the same route – except for slight variations near their terminus.

That’s not to say you can’t go too far in the other direction as well – over-simplifying the network. While I would generally consider Auckland’s bus network to be over-complicated, some of that complexity has a useful purpose – like express and short-running buses on Dominion Road, or peak services that do extend to parts of the city (for example, Chatswood on the North Shore) that wouldn’t have the ridership to justify an all-day service. While I generally support the simplification process proposed in the changes to buses in the central city – I do wonder whether there’s the opportunity to overlay some peak-time express services (particularly on the 020 route) to give people what they really want at peak times: a fast and reliable service. I’m not quite sure that the 020 will provide that with its detour through Freemans Bay:

A good bus network is largely dependent upon the street network that it has to work around. Possibly the best bus and most effective bus network that I’ve seen is that in Vancouver – enormously aided by its gridded street pattern:

The gridded system enables so many “win-win” outcomes. By running buses along the major corridors (both north-south and east-west) all the routes generally operate in the fastest possible way, but they’re close enough together to ensure that everyone’s within a few minutes walk of a bus stop. So we solve that speed versus accessibility issue. We also solve the complexity issue because the routes are simple and easy to understand – they go along a particular road for most of their journey. Even if there are variations (express services or some variation from branching close to the route’s terminus) these are fairly easy to understand because the vast majority of the route is simple.

It’s not surprising that Auckland’s bus system seems most successful and effective in parts of the city with a street pattern that most clearly follows what’s in Vancouver. By contrast, the street pattern in the eastern isthmus makes a legible bus network nigh on impossible (although I’m sure we can improve on the incomprehensible mess that’s currently there.

There are of course many other issues to balance. Do we have stops further apart (faster journeys) or closer together (shorter walk to the bus stop)? Do we have long routes (allowing a lot of trip possibilities on the one route), or shorter routes (probably improved reliability)? And of course the big question – do we design a system that seeks to avoid transfers, or do we design a system that takes advantage of the benefits offered by transfers? Each has their pros and cons.

Clearly there’s no single best way to design a bus network in my opinion. But that doesn’t mean we can’t significantly improve on what we’ve got in Auckland. If you look at Auckland’s bus network it generally doesn’t seem to have got the balance right: it’s overly and unnecessarily complex – seemingly a relic of 1970s thinking which was “the more routes the better”. Furthermore, I tend to think that Auckland’s bus network doesn’t get the balance right when it comes to speed versus accessibility either – with a few exceptions such as the Northern Express route, it seems as though the bus network has been designed with the assumption that it’s only there to serve people who can’t afford to drive or aren’t able to. It puts accessibility too far ahead of speed – meaning that we end up with a huge number of very very slow and windy bus routes.

A lot of the problems with Auckland’s network are historic – based on assumptions that buses are only there to serve those with no choice, based on extremely poor integration with the rail system and generally based on a desire to avoid transfers at all costs. While we must be careful not to go the other way too far – and I think many routes could handle increased stopping pattern complexity (i.e. more express services and short-runners rather than all buses having the same stopping pattern) – overall to give the network a better balance we should be aiming to simplify and to speed things up.

Share this