This graph shows what percentage of trips were made by bike in Auckland from 2003 to 2011. It is done on a rolling 2 year average of survey results. I have included Wellington and Christchurch to give a comparison.
However, as you can see, this graph is not very exciting right now. There does not appear to be massive, double digit growth in cycling rates (as a percentage of all trips) going on in any of these cities right now.
These graphs are based on the Household Travel information Survey which is probably the best source of info we have on cycling rates but WARNING WARNING is still probably not that reliable.
This is largely because the number of cyclists in the survey in any given city is so small (ranging from 20 to 60) that it may be difficult for them to accurately extrapolate to work out the total number of trips made by bike.
I guess you could potentially interpret this graph as showing a small increase in Auckland cycling rates, from 0.26% of all trips to 0.83%. But I doubt it would be a significant trend, although I don’t have time to analyse it myself.
But that’s ok! Because in future our brilliant advocacy (and rising petrol prices) will make the graph look like this.
Right guys? What do you think? Am I being too optimistic or too conservative in thinking we might achieve 5% mode share by 2017? Perhaps the goal should be for 2022 instead. What do you reckon?
It may be a little self-serving, but should we not instead use the COMMUTING mode share when we discuss this? Which is a lot higher for bikes than this, from memory. I certainly remember that Christchurch’s cycle share was higher than 3% in that type of count.
I think it is a little self serving
although it is important, you are right, because most transport infrastructure is built to serve peak time demand.
I am not sure if there would be much info available for that. But i shall look it up.
I depends how you draw the graph — look at my version here: http://imageshack.us/photo/my-images/193/cycleshare.jpg/ It makes it clear that cycling has more than tripled its mode share in 6 years. If that trend keeps up, we could expect cycling to triple by 2017, so achieving levels seen in Christchurch currently.
Given the sample size for the survey (4600 househols and every person in that household), you’d expect that these numbers would be very accurate. So the trend is both practically and statistically significant….
You paint these numbers like a bad news story — cycle mode share has gone from about 0.25% to nearly
sorry, meant to get rid of that last sentence…
Looking at the sample sizes again, I see that the Auckland sample sizes are pretty small for earlier years (only 824 people with any trips in 2003-2005) so estimates based on those number are probably not reliable. But the gap between 0.25% and 0.9% is big enough that it can’t be put down to sampling fluctuations.
But with the bigger samples they do now (nearly 4000 people), changes of about 0.4% would be considered statistically significant (that is, not merely due to sampling fluctuations).
Having cycled in several US cities recently that have modeshare in the order of 3-5%, I was quite surprised at what a difference 1% is c.f. 4%, doesn’t seem like a big difference but you really start to feel that there are many other cyclists going about their business. It’s certainly not the paradise that is cycling in Germany or the Netherlands, but I think Auckland just needs to lift its numbers a wee bit in the next few years to really get the ball rolling. Once we reach these numbers I think we have the critical mass to start making our presence felt in transport planning circles – rather than being rounded down to 0% as occurs at the moment.
hi David. I would be interested to see an analysis as to whether that increase is statistically significant. I don’t have time to do it but if you do then please go ahead.
I am sorry if you think I am taking a negative stance – I don’t want to sound negative but at the same time, I don’t think it is a good news story that cycling mode share in Auckland is below 1% and has been that way for 10 years. Nobody will be happier than me if the increases we have seen in the last few years continues – but I think it is too soon to be confident this trend will continue.
@ bbc. I agree. Cycling is much more visible in Chch and I felt safer as a cyclist there than in Auckland (this is pre-earthquake, it has probably all changed a lot since then in ways I can’t comment on, not having visited the city since about 2009).
Roughly, the difference in two sampled proportions, p1 and p2, is significant when the difference pd = p1-p2 is greater than 1.96*the standard error of the difference. The standard error at 1% is about sqrt(2)*sqrt(0.01*(1-0.01)/n) where n is the sample size. In later years n = 3800, so 1.96*se is about 0.45%. So for numbers around this level, any difference of more than 0.4-0.5% is statistically significant.
last time I looked at this survey, I decided that it hugely underepresented Auckland in the sample so I haven’t bothered with it, probably in the last 10-12 years
Steve, as the above suggests, the survey is now large enough to pick up relatively small changes in behaviour. It’s worth a look..