Number of motor vehicles

Hi Guys. Thanks for linking to the Transport blog.
Yes, there's a long and interesting history of census questions changing and reflecting what government is interested in measuring...
Re the wider issues identified in the blog this is just what we want to bring into the discussion - thanks. This is good and as much as possible let's try and keep each discussion thread focused on the specific question being discussed.

I've past your question to a colleague who's been involved in the deprivation index and will pass on their comments... yes there's a growing number of people using other modes of transport and choosing not to own a car and we'd to get a picture of this.

If you asked the number of motor vehicles available to the individual would that also replace the same question on the Dwelling form? Or would both be there?

Knowing how many vehicles an individual has access to is interesting but as much as knowing how many vehciles are on a single dwelling at one time.
As with the individual you will get double/triple counting of the same vehicles as each householder could claim they could drive any of the vehicles at the dwelling.

Also concerned about its misuse of this statistic as a proxy for the deprivation indicator. There must be better and more reliable indicators we can use for this information than number of cars, and we should ask those questions on the census instead of this one if needed.

Yes data on the number of motor vehicles is used to calculate a person’s deprivation index rating.

However, it is worth noting that the deprivation index is separate from the Census, albeit using Census data. Either way, the deprivation index is a composite indicator, which consists of nine variables. See NZDep2013 Index of Deprivation for more details. Access to the internet (for people aged under 65) currently receives the most weighting and the weigh given to the number of cars is relatively low.

I gather that the calculation/index is not perfect – but on balance they find that the number of motor vehicles provides a useful indicator of someone’s deprivation.

Re the question about what form(s) the question about the number of vehicles would go on, this hasn’t been decided… whether the question goes on the individual form or dwelling form depends whether people would find it more valuable to collect information at the individual level or dwelling level. (Questions about whether/how we could address some of the complexities of collecting at an individual level could be addressed subsequently.)

Just in case I’ve missed the point can you please clarify whether you would find it more valuable to have information at individual level or dwelling level? And do others have any thoughts on this???

I don't have access to a motor vehicle. I don't feel deprived (in fact like a lot of apartment dwellers, I'm relatively high income, and have lots of discretionary spending because I don't have to have a car). One of my sisters was in a low income four car household because they had no choice (semi-rural location. Definitely deprived because the transport costs meant they struggled to buy basics like food and boots for the kids work. So as a measure of deprivation, car ownership is totally misleading.

I don't have a licence, and as a result I am transport disadvantaged in some circumstances because of the way the transport system operates. That's a measure worth having (see below).

I have found statistics on proprtion of households that are car-less useful. Statistics on numbers of cars useless - you can't tell why they have them (they collect old cars, most of them aren't working, they are looking after one for someone overseas, they drive them every day to work/school). If you want to ask about numbers, then ask about cars that are regularly used by the household for transport purposes. But as I said, I've never found a use for that statistic.

I would be interested in statistics on whether carless households use car share or similar arrangements, or regularly borrow a car from someone else. Or do they happily (or unhappily) live without a car. So a question with three choices - household has a car or motorbike, household regularly uses a car that does not belong to the household (including commercial car share company), household does not have regular use of a car or motorbike.

To me motorbikes are just small unsafe cars. If they could be separated, fine, as they are highly unsafe and a trend of increased use is worrying. But I have no problem with them being lumped as they largely use the same type of infrastructure and create the same kinds of problems for other modes.

I would love to see statistics on number of individuals who can't currently drive a car (reasons why they might not include no licence, enforcement conditions stopping them driving, health stopping them using their licence). The ones I've been using are very old and unreliable (30% of the population without a licence). And they matter a lot in terms of discussions about effects of transport infrastructure choices on transport disadvantage.

I would be interested in knowing if households have other things they regularly use for transport purposes, including bikes, scooters, rollerblades, mobility scooters, wheelchairs. That will give us a sense of what our infrastructure needs to cater for, and what trends in use of new technology (e.g. push scooters) are, and how use relates to demographics (age for example).

Agree that the number of cars is a bit meaningless. No car households tell us a lot. The number of cars in a household might tell us something about parking issues - how many are on the public road/privately located? Another aspect is how close access to public transport is. Places well served with PT that have high numbers of car-less households are not necessarily deprived - as Paula says. Whereas car-less households in the country with no PT are quite different. Larger numbers of vehicles per household become a space use issue.

Thanks for all the great ideas. Point taken that the maybe limitations with NZDep... I'm simply not qualified to answer one way or the other. However, I don't think it's really relevant to the discussion here...
What I'm hearing of interest is that you seem to be interested in information about what options/opportunities people have fro travelling and accessing public amenities and other facilities (rather than a simple measure of people's material possessions)???

Hi John,

I'm hearing two things distinctly. One is as you say, all the options and opportunities including PMV for getting to and from A to B; PMV, Cycling, Walking (not all areas have footpaths and not all people can walk), Bus,train, and ferry. Useful? I reckon overtime absolutely, which is important for the Census.

We might lose continuity of the actual PMV datapoint though depending on the question.

The second is that, given the this is the PMV question, clearly there is value in knowing the number of PMVs people have access to for transport planning in the medium term, but equally important is the boundary case of zero cars, and for this group the important metric is why (which is too airy fairy for a census), so really how important/what value zero is to individuals.

Two tensions there; data on medium term issues like transport planning and allocation of resources (are minimum parking regulations needed if a population doesn't own cars) and longer term trends about all the modes people have access to/use over time.

Side bar: NZ Stats need nominating for feedback process/mechanism award. Great to see genuine, honest, human feedback on the feedback!

Yes how many places don't have footpaths or safe walk ways to get about on. Or no access to public transport

I think this discussion has confused number of cars with other questions about modes of transport,( which could also be altered for better detail.)
Surely the number of cars is simply a household asset like number of bedrooms. We don't ask how many are beds are slept in etc, just like we cannot work out how the cars are used.
I have seen lack of cars being used as a filter to target low income households for mobile direct marketing, so it does work.
All of the simple census questions throw up all sorts of related issues don't they? It's never so simple because the definitions are so undefined. Even if the explanations were expanded to help a respondent to decide the number to enter, would we as analysts know how they made the decision?

Self employed users must have trouble with this question because all their vehicles are dual use. I would think it would be better to include "all vehicles used from the dwelling". That would then allow for pickups which are 40% of new car sales currently.

I think the relationship between car ownership and household poverty is no longer reliable. Many poor households have a lot of cars, while high income young people have none because they choose not to. If we are only interested in them as a household asset, I'm not sure why, unless it is to measure drag on the economy (as they represent a lot of money tied up and not able to be used productively). Similarly, we wouldn't use number of bedrooms as a measure of poverty (I hope) - number ofbedrooms per member of the household would be relevant.

You missed the point Paula. The zero cars was used in conjunction with low income households which is another statistic already directly available.
There are difficulties with combining counts from different variables because the summary counts are not for the same household but it seems to be done anyway and apparently gives useful results. The driver could be directed to a meshblock with high counts of low income, high counts of zero vehicles and lots of children to target single parents likely to be stuck at home. It was so accurate in my own locality that I could name the street before I zoomed in.
The census does not identify individuals but it does classify areas because "we are where we live."

I'm definitely missing the point here. I can't see car number as a proxy for poverty, as lots might indicate poverty or it might indicate wealth. I can't even see "no car" as a proxy for poverty, as bits of cities with high "no car" patterns are now probably CBDs full of apartments and young people (30% of CBD apartments in Wellington are car-free). If you have to combine it with data on income, then I don't know why you need the car question as well.

Maybe we could agree that no car is a co-variable with income.
Because they are targeting consumers with no transport and no cash to market hire purchase of household linen and children's clothes. And who could not travel easily to the shops. The location of rich consumers with no cars and access to shops with public transport are easily filtered out. It might seem unfair, but it is not an individual judgement it is a pattern for an area.
Each of these variables can be added together to make a custom deprivation index that suited the purpose.
Note that gender is not involved, but you could guess that the majority of these would be solo mothers. A low income household with a car would not be useful for a mobile shop.

Thanks for interesting discussion and working to clarify and reconcile your ideas :)
Having clarified that the number of cars maybe a co-variable that can be combined with data for income to identify areas that have certain income levels and no access to motor vehicles...
Aside from being used by hire purchase companies to inform marketing campaigns, what other concrete examples do people have of where information is needed re the number of motor vehicles (either as (limited?)measure of household assets or as a indicator of mobility?
Thanks

Vehicle parking is a hot topic in urban areas. It requires space. The more vehicles there are the more space they need - either in private or public spaces. So could be useful for managing/planning space which is likely to become more of an issue

In relation to the mobile shops, a better use in that case woudl be for a consumer organisation to target the households and educate them about the perils of mobile shops, and for councils to target those communities for bus services.

Jane Turnbull here, at Otago Regional Council
We have found data about the level of multiple motor vehicle ownership in census area units and territorial districts useful for a couple of purposes: (1) helping prioritise investments in improving particular bus routes ; and (2) helping understand vehicle ownership as a potential barrier to getting more people on buses where this may be desirable in order to reduce congestion (eg in Queenstown).
The data about the proportion of households owning more than 3 vehicles in particularly useful and I would like that data to be readily available on the Stats NZ website for local govt. planning.
It would be useful to break down the data by the type of vehicle, motorised and non-motorized.

Is there a good reason for limiting the definition of motor vehicle to those with four wheels? I believe scooters and motorcycles are increasingly used, particularly in urban environments. Understanding trends in this category may be useful for planners.

Hi Jane. Good to know you are still down there.

Anette's point and your use of the data takes me back to the need to distinguish vehicles that are used for transport purposes (including bicycles, electric bicycles, etc) and vehicles that aren't (the hulk in the garage that doesn't have warrant of fitness, the vintage car only taken out for events, the quad bike only used on the farm).

I have read through the discussion so far, and I think an important point is missing. I am interested in the availability of cars to people and households. The information is highly valuable when interpreting/analysing for any corridor-based traffic issues or new services. I think it is important if a household has access to a car or not, (zero car stat), but it is also important to know how many potential drivers in a household do not have access to a car. A zero car HH will always need to use an alternative to travel. A one car HH with two drivers who both go out to work? - one of the drivers must be traveling as a passenger. A two car HH with two drivers, where one of the two takes the bus, train, or carpools to work? - that person is a 'choice rider' and highly important to a future with reduced traffic congestion.

It is important that HH vehicle count INCLUDE work vehicles, or at least the reporting of HH vehicle count include if one of the occupants drove a company car, truck, or van, or else the 'zero-vehicle HH' statistic will be misleading.
I also think that there should be a question about drivers licence (do you have one?) for everyone 16 years plus.

There will be a danger asking individuals about access to vehicles unless the HH vehicle question is also asked - two people could have access to the same one car, and of course could not both use it at the same time as the driver.

The motor vehicle question as it is currently worded does create issues for people living in shared flats. These are considered as one household when in fact they consist of a number of people with totally separate assets and finances. There may well be a number of vehicles and licenced drivers in one and the same flatting household, but there may be people who do not own a vehicle and therefore have no access to any of the vehicles. And those who do own a vehicle, would have access to one vehicle only not say the 2 or 3 that may be located in that household. So the question will be answered inconsistently across different shared flat households depending on how they interpret this question. Given that shared flats are quite common in NZ, and not unusual even amongst high income earners, I wonder in how far these people are correctly represented in the data.

We are working on a proposal for an electric car-share system in Auckland, and finding the statistics require some interpretation to help us understand the true number of zero and one vehicle households. Statistics from Seattle show that 26% of members are from HH that have no cars, and 42% from HH that have one car. Is a HH that has no cars, but does have one that is able to be used only for work (so not included in the answer) really a zero-car HH?

So in the last census we had zero cars, but because I know about CityHop I specified I had access to a car.

The issue with the census question is that it asked if you had access to a car. Not if you had a access to a car on the premise.

So the four people here answered yes because we potentially have access to and use CityHop, not that we have a car available on site.

If Seattle has a car share system you need to assume that some people will consider the availability of a car share system a PMV they have access to even if that wasn't the intent of the question (assuming questions were not specific enough to distinguish on site, and 'available')

Something to think about.

Benjamin's point is a good one. We expect car sharing to increase over time (and in fact that's desirable). There are also other arrangements people make - my niece at one stage had access to my mother's car, but it was stored mostly at my mother's retirement village.

Basically everyone with a licence and a little discretionary money has access to a car if they choose to do so. It's not just carsharing, but also rental vehicles which you can get whenever you need. Then you have people who are not licenced drivers (by choice or for other reasons) and there might very well be a vehicle available for their use but they actually cannot drive the vehicle themselves. But one could argue that the vehicle might still be available FOR THEIR USE as if they travel as a passenger, they in fact still use the vehicle. And then there may be others who even cannot use the vehicle as passengers as they might be in a wheelchair etc. So what it comes down to is that the wording of the question as it currently is does not tell you with accuracy: 1. the number of motor vehicles located at a given household; 2. the level of availability of motor vehicles in that household or anywhere else to the INDIVIDUAL household member; 3. the actual ability of the INDIVIDUAL household member to in fact drive the vehicle available to them; 4. the actual ability of the INDIVIDUAL household member to use a vehicle as a passenger.

Ulrike's points emphasise the fact that it is people's likely degree of transport disadvantage that someone like me is interested in. You could think of the individuals as being on a spectrum - I have a licence, a car, and money, and am in a city with a PT system, and I'm not disabled, so I can choose any mode and do any trip; I am in a household/relationship that has those, and I'm not disabled, but I rely on someone else to use the car; Ditto, but I have a disability that limits my choices; I'm missing something on the list, so am limited in mode choices but not significantly limited in access; I'm missing something on the list and that means I'm restricted not only in choice but in access to things that matter to me (education, job opportunities, recreation opportunities, etc).

Thanks for the great ideas and discussion. And welcome to all those who've joined into the discussion.

There are clearly many many potential complications and possible questions we could ask, different ways for the respondent to interpret/answer questions, and many different types of information we could collect... So thanks to all of you who focused on what information you would find most useful and why.

What's at the top of other people "information shopping list"? And why?

A few clarifications about why information is collected about motor vehicles only and what's included in the count:

A reason to ask about motor vehicles and not other types of transport is that other types of transport have limitations that motor vehicles do not have. For example, motorbikes, scooters, and bicycles may not be suitable forms of transport for small children and elderly people. Another aspect to consider is that other forms of transport a household has (eg bicycles) may not necessarily be in use.

Because the motor vehicles data is about those available for private use, excluding any for work purposes only, it indicates the number which households have unlimited access to for any purpose, including transporting children, visiting family and friends, going to the doctor, going to sporting events, concerts etc. If a vehicle is only available for work purposes then it’s of limited use. The data on main means of travel to work provides some information on use of work vehicles.

Although the number of motor vehicles data hasn't been restricted to vehicles used regularly for transport purposes, respondents are asked to exclude those that are borrowed occasionally from another household, and (in the guide notes) those that are likely to be off the road for several months.

This is exactly the issue - a flat in reality does not constitute ONE household, it's a number of separate households with separately owned vehicles. As the question is currently in the Census, there is no way for flats to answer this question accurately. E.g. someone sharing flat with 2 other people are considered one household by the Census. There are 2 cars available for private purposes. BUT each of these cars is owned by one individual flatmate i.e. two flatmates have access to one car each (not 2), and the third flatmate does not own a car i.e. has no access to a car. So there will be many zero car "households" hidden in the Census data at the moment. And get gaining a sense of the true number of zero car households would be important for urban and transport planning purposes.

This raises a good point. In the census a 'household' is defined as a group of people living together and sharing facilities, or a person living alone. Under this definition, unrelated people living together are a household. So in the example above, the correct answer to the motor vehicles question would be two. Because this data is household level, not all household members necessarily have equal access to these motor vehicles, depending on the type of household. However, it is possible to gain insights into the numbers of zero-car people within households using the existing data - this could be done by cross-tabulating number of motor vehicles by number of usual residents in household by household composition. In the household composition census data, there is a separate category for households consisting of unrelated people.

One thing I am quite curious about with this - Has any thought been given to capturing how many off-street parking spots a home has access to? Currently this is a massive black hole for local authorities - because of the staggered timing of parking regulations since the built environment of the city began to form, it is often difficult to know whether an area has higher or lower access to parking - and this would arguably be a more useful measure for planning parking policies. Combining the two would be incredibly powerful, and it wouldn't be too difficult to put a tickbox for each next to each other. I recognize that this is fairly urban-focused(assessing the number of parking spots on a large farm would, for example, be challenging) because space is at a premium, but it would be incredibly useful when paired with the number of cars available.

The number of motor vehicles is important, I do have sympathy for the idea that bikes, motorbikes, etc. should be measured too - would having a matrix question not fairly easily fix this?

Numbers across the vertical axis in categories, with "num of cars, num of parking spots, num of bicycles, num of powered cycles" across the top. Not a big change.

@angela(topicexpert) says: "A few clarifications about why information is collected about motor vehicles only and what’s included in the count:" but really only explains what is included, not really 'why'.

Is the vehicle access question a throwback to days gone by when having a car was the only way to get around? What was the policy environment when this question was first asked, and has it remained the same due to convention over the years? Was the reason for asking the question about civil emergency preparedness? Was it really as Angela implies to know if people from the household could all go anywhere without limitation? If so, why was that the important distinction? I think there was a time when the increasing number of vehicles per household was seen in a positive light as an indicator of increasing wealth of the nation: now we are in a different era when policy direction is shifting to a strong interest in households avoiding at least the second car, if not the first. What I think commenters on this group are more interested in is 'means of mobility', and as such, having a more comprehensive view would be valuable.

Agree with Paul Minett that a broader view of mobility is required. A simple way to achieve that would be asking what other vehicles a household has, e.g. motorcycles, scooters, bikes, etc. But IMHO this does not yet approach the more interesting question (and one that might contrast with the one about how people got to work/education on Census day) of what people's key means of mobility is. Or what patterns and proportions they use mobility in.
For example, we have one car in the household (two adults and one toddler) but it is basically only ever used on weekends, and even then not every weekend. I am sure there are one-car households where the car is used intensively every day.
Means of mobility are diversifying, especially in central city areas but also in suburbs. How do we avoid oversimplification and ignoring diversity of mobility, but then avoid overcomplicating the Census in trying to capture a diversity of mobility patterns? Tricky!

Oh, and to echo Max's comment at the top - thanks to the 2018 Census team on using Loomio to engage and capture rich opinion data!