The Laws of Physics, Modelling & Future Transport Scenarios

In our February eNews, we met Andy Ford, Manager of the Wellington Transport Analytics Unit (WTAU), to learn about the work they do.

This month, we meet Christoph Gerds, Team Leader at WTAU, and learn about the laws of Physics, Modelling & Future Scenarios. Specifically, Christoph shares a brief overview of a couple of projects that WTAU have worked on with the Wellington Regional Leadership committee – the FDS and WTERP. To expand on the acronyms:

• FDS – Future Development Strategy, the process of developing an agreed strategy for how and where the region can accommodate the up to 200,000 people who might call the region home over the next 30 years 
• WTERP – Wellington Transport Emissions Reduction Pathway, which outlines pathways for the region to achieve a 25% drop in per capita VKT and transport emissions by 2035.

Q Can you share a bit about your background?
A I was born and raised in northern Germany, near the harbour city of Kiel. That’s also where I studied Physics. After graduating, I spent some time in India, followed by time in Norway, and eventually ended up in Wellington in 2007. 

Q Physics, hm… So how did you end up in transport modelling? 
A They’re less different than you’d think!  Both physics and transport modelling involve trying to describe the world using mathematical models. This does ofcourse mean a lot of computers and programming.  

Q Which WTAU projects are you sharing today?
A I’d like to give an overview of some work we have done for the FDS and WTERP. 

Q WTFDS?
A Almost! FDS stands for, the Future Development Strategy. The process of developing this strategy involved significant research, analysis, consultation and engagement, to develop a regionally-agreed strategy for how and where the region can accommodate the up to 200,000 people who might call the region home over the next 30 years. The WTERP is the Wellington Transport Emissions Reduction Pathway, which outlines pathways to meet our climate goals.  

Q Can you outline WTAU’s role in the FDS and WTERP?
A We have looked at a number of different future scenarios, which means – different assumptions about where people live and work, and what the transport system might be. For that, we used our big transport model called the Wellington Transport Strategy Model (WTSM). 

Q What were those scenarios, and what have you found out?
A For the FDS, we looked further into the future, where we expect quite a few more people to live in the region. Our scenarios model a future roughly 30 years away. We expect an additional 200,000 people living in the region by then. So one of the big questions is, where exactly will they live, and how will they get around? 

Q And your WTSM model can do all that?
A Partly… The model can’t tell us where people will live, or what the transport network will look like in 30 years time. What the model can help with is to say: Assuming this is how the network looks, and assuming where people will live, what does that mean for how they’ll likely get around. 

Q That’s a lot of assumptions…
A True, but these are also the things we can influence. I mean, not me necessarily, but politicians, the WRLC and so on. 

Q Can you share more about the WTERP?
A Yes, so for the Wellington Transport Emissions Reduction Pathway we have looked into how the transport system has to change so that we meet our climate goals. For most of this, we have looked at a shorter time frame, more like 10 years, out to 2035. With this shorter time, we don’t expect so much population growth or change in the urban form.  

Not saying that that is not important, it’s hugely important to set the right course now.  

But, with not much chance to fundamentally change the urban form within 10 years, the question is what can we do? One obvious answer that people often jump to is electric cars, but again, over 10 years that will fall way short of where we’ll have to be. Essentially that means we’ll have to make up the shortfall with driving less.  

Q How much less? 
A In the WTERP, the aim is for a 25% reduction in VKT per capita, (Vehicle Kilometre Travelled.)  So basically, we’ll need to reduce the distances we drive daily by a quarter (on average, of course). For some people it might be more, for some less, and some may even drive more than today. An average 25% reduction in VKT is a huge goal. 

Q So, how do you model that?
A Basically, we pushed the model to it’s limits, and then some. What I mean by that is, we took every lever commonly used in the model and pulled it as hard as plausibly possible. So for example, in theory we could put in a bullet train from Masterton to Wellington, but that’s not plausible. So instead, we put in improvements in rail-frequency that are ambitious, but realistic. 

Q Anything else? 

A Much more: Bus lanes and more buses throughout the region, improvements for active modes like cycle lanes on steroids, also 30km/h speed limits in all residential areas and centres, parking management, Traffic Circulation Plans… 

Q What are traffic circulation plans?
A The idea of a traffic circulation plan is that you disable through-traffic from an area by strategically blocking off certain connections for cars. You can still drive to most places, but it becomes more convenient not to drive. 

Q Speed restrictions, blocking off cars… don’t people hate that?
A The funny thing is, once in place, and done well, the experience shows most people really, really like it. 

Q OK, so you put all these things into the model and then we meet the climate targets?
A No. 

Q No?
A No, we put all this in, and we are still short. So, we also put in some additional pricing mechanisms, road pricing, congestion charging, time of day pricing, something like that. We have modelled a specific version of course, but that’s not set in stone. 

I also want to mention that, the model doesn’t tell us everything, but it can give us a good sense of the direction and of the magnitude of change required. 

Q Don’t people strongly dislike the pricing?
A Only to some degree, if they can see the benefits it brings, most folks seem to be OK with it. Also, economists love it. So, it’s palatable to both sides of the political spectrum, which is always a bonus. But what is important is that road-user pricing must be accompanied by affordable, reliable and safe alternative modes, such as improvements in public and active transport. Without viable alternatives to switch to, it risks being seen just as another tax, and an anti-car penalty, that few people would support. 

This is also a general rule, the WTERP highlights how important it is to take actions as a suite of interventions, not in isolation. 

Q Any final words?
A Sure. That the future we’ve modelled for the WTERP not only helps meeting out climate targets, but by giving people choices it’s also a healthier and a cheaper future than one where people are more reliant on their cars to get around. 

Follow the work of WTAU here.