The world would be a much better place if transport operators would stop spinning patronage numbers to the media and public and start giving us the salient facts instead.
The Financial Review reported on Thursday that travellers in Melbourne aged 20-29 years comprise 38% of all public transport users in the city. This figure is in line with the claim of the WA Public Transport Authority that 18-25 year olds comprise 35% of all train users in Perth and 40% of all bus users.
As I’ve indicated before, I find these sorts of figures very hard to believe, given these two cohort’s each comprise around 15% of the population. In fact they’re extraordinary. It’s true young adults have always been over-represented on public transport because many are on relatively low incomes, but it’s the sheer scale of these figures I find too good to be true.
The reality is they’re not true, at least for Melbourne. The real situation is shown in the first exhibit. According to the Victorian Department of Transport’s VISTA database, travellers in the 20-29 age group account for only 22.3% of public transport users on an average day. If confined solely to the average weekday, the figure is a little lower, 21.9%. If instead we look at public transport boardings – to allow for the possibility that young adults make more multi-modal trips than others – the proportion in the 20-29 age group using public transport is a little higher, but still only 22.9%.
That’s a long, long way short of 38%. One explanation for this evident discrepancy could be that public transport operaters are measuring something else. VISTA is a snapshot of travel on a typical day, but it could be operators are counting the number of people who have ever used public transport – even if only once or twice – in some preceding period e.g. in the previous week, month or year. This will invariably give a much higher total patronage figure than VISTA or the Census because it picks up everybody who’s used train, tram, bus or ferry at least once during the (longer) period.
If this explanation is right, it would account for why claimed patronage levels for public transport are sometimes breathtakingly high compared to the customary, more rigorous ways of measuring travel. I’ve commented before on Metlink’s use of these sorts of inflated, self-serving numbers in its marketing material, but perhaps it’s a common practise in other states too. But by itself this explanation doesn’t fully account for why the young adult cohort’s share is apparently so high relative to others (see second exhibit). Read the rest of this entry »