Recently Thomas Lumley, a Professor of Biostatistics at the University of Auckland and author of statschat and Biased and Inefficient, created a bot that follows Auckland Transport’s real time feed between 6am and 10pm and tweets every 15 minutes how many buses it can see active in the system and how many of them are on time.
I thought it might be interesting to track the results for a week to see if there were any trends with on time performance, such as during the peaks. The data I collected for on-time performance was interesting but what turned out to be more fascinating was the overall bus numbers. The graph below shows how many buses are active in Auckland throughout the day based and you can see that weekdays have a very similar and distinctive pattern to them.
I’m not sure the peaks could be any more visible if AT tired.
As you can see, the AM peak is by far the strongest with over 800 buses on the road at the highest point which occurs around 8am as people go to work, school or other activities. There are more than double the number of buses on the road during the peak than throughout the interpeak period. The evening peak is more spread out though reflecting that schools finish at around 3pm and that workers finish at a range of different times and/or have other activities after work.
But being so peaky, especially in the AM, is a bit of a double-edged sword. On one side, it’s a positive as it reflects a lot of people finding PT the best way for them to get around to work, school or their other activities and of course we want to encourage as many people as possible to use PT. On the other side of the sword, being so peaky means AT and its operators need to commit a lot more resource to the system than they might want or otherwise need, just to serve the customers they already have. That pushes up costs to run the network.
To get an idea of the impact, let’s consider what would happen if could knock the top off AM peak during the weekdays and spread it out more. During the AM peak, bus numbers top out at about 830 buses while the busiest period in the PM peak is about 710 buses, a difference of 120 buses. From what I understand, an average bus can cost around $400,000 (even more for double deckers), that’s potentially $48 million of capital operators have tied up in bus that might only get used once or twice a day. On top of the capital costs of the buses there is also costs for larger depots, maintenance facilities – 120 buses take up a lot of space. On top of the capital costs are of course the operational ones and they can be substantial.
Trying to spread out the peak could have a lot of positive impacts for the overall PT network. Here are a few suggestions we could implement.
1. Add more bus lanes and bus priority
Adding more bus lanes and other bus priority measures is vital as they are able serve a number of purposes. Faster and more reliable buses help to make buses more attractive to users, growing ridership, but they also improve bus operations because they can mean a single bus might be able to run more services in the same amount of time. This means fewer buses are needed to provide the same capacity/frequency or alternatively more capacity/frequency can be added to the network for no additional cost. In effect this isn’t likely to reduce the peakiness but it can help reduce some of the additional cost associated with it. As we reported the other day, it appears AT are looking at more bus priority across the region.
2. Extend bus lane hours
This is kind of related to above but is worth highlighting on its own. Many bus lanes have very narrow windows during which they operate, often 7-9am and 4-6pm (although there are some other times). Outside the bus lane hours the road space is often handed over to the driving public for carparking. It’s common for drivers to target these hours in order to get a good space but given the roads are often still quite busy, it can cause havoc on buses driving around the city, making them less reliable. As such means passengers often try to catch earlier buses than they otherwise would just to ensure they get to their destination on time. Extending bus lane operating hours would help address this and make travelling on later buses more viable, spreading the demand.
3. Off-Peak discounts
Along with extending bus lane hours, it’s common for cities overseas to offer discounts for travelling off peak. The purpose is to use pricing to encourage people who can to travel at times when it’s not so busy and there’s spare capacity available. There are a couple of different ways it could be implemented, such as having it automatically apply when you tag on/off or having people buy a pass that is loaded onto their HOP card and entitles them to the discount. AT staff have told me in the past they want tools like this so we’ll just have to wait and see if it ever happens.
4. Improve Frequencies off peak
Along with improving bus priority and offering financial incentives to travel off peak, we also need to ensure that our transport network has the services needed to encourage use. In other words, not having half the buses disappear back to the depot at 9am. This is one of the key reasons the New Network is so important, as it creates a lot of strong all day network that people can use to get around.
5. Change school hours
As mentioned, everyone rushing to work and school at the same time of the day is why the morning peak has so many more buses at any one time. One option could be to shift the start times of some schools to later in the morning in a bid to spread out the demand. High Schools would make a perfect candidate for this, giving teenagers a chance to get more sleep and perform better. This is obviously outside of AT’s control but is a discussion we should be having as a society.
For those also interested, this is what the punctuality data looked like, you can see the peaks in some of the days but it’s not as defined as the bus numbers above.