Older people’s travel patterns & transport sustainability

It is common knowledge that the "older" population segment, meaning those over the age of 60, is rapidly increasing as a proportion of the overall population within New Zealand. What is not known, however, is their effect on transport sustainability, particularly the growing problem of emissions and other environmental and health concerns. Are their average annual kilometres travelled per person increasing? What could their contribution be in 5 or 10 years time? Is there a need, apart from safety reasons (due to infirmity for example), to modify their car use? What is the best means to do so?

Australian research suggested that the combined impact of more older people, a higher proportion of seniors with licences (especially women), and increasing kilometres travelled could have surprisingly dramatic effects on outcomes. For example, the potential for a 175% increase in fatal and serious injury crashes has been found (Richardson & Bell, 2001).

We updated the earlier study of older people's travel patterns using 1997/98 New Zealand Household Travel Survey (NZHTS) with a comparative analysis using the recently compiled 2004-07 Ongoing NZHTS database (ONZHTS) to identify the travel patterns, particularly by private motor vehicle, of the older population segments in New Zealand.

Between 1997/98 and 2004–07, older people as a group increased their volume of travel considerably, especially their driver trips (from 174.5 million per year to 364 million) and distance driven (from 1040 million km to 2500 million km). Older drivers (60+) formed a significantly higher proportion of the vehicle traffic stream (18% compared with 15%) in 2004–07. As the mean distance driven per day per person did not change significantly for older drivers, the increased share of the traffic stream appeared to result from the greater number of older drivers in particular. However, as both their trip-making and kilometres travelled were at much lower levels than for those aged 25–59, older people probably caused less pressure on the transport network, especially since the majority of their trip segments (60%) occurred during the 'off-peak' hours of 9.01 am to 3 pm.

Having developed a basic understanding of how this population travelled, we reported on:

  • Contrasts with the travel behaviour of younger New Zealand adults (in the three largest urban areas)
  • Whether there was a need to influence or change their car use
  • What impacts any policies or actions (such as peak time charging mechanisms, increased parking charges, etc) taken by government could have on their ability to move around
  • What policies or actions may best be targeted to this group of people.

Our analysis suggests that, over the next 40 years, as older people become a greater proportion of the total New Zealand population (predicted by Statistics NZ (2007) to increase from 12% to 25% or more), there will be a discernible impact on the overall travel patterns of New Zealanders. For example, as older people form an even greater proportion of the vehicle traffic stream, among other things, there may be noticeable differences in the amount (both quantity of trip segments and their length) and timing of travel on the roads and public transport; overall vehicle kilometres travelled per day per person may decline; and walking as a mode share may increase. Of course, some of the change may be masked by overall population growth in New Zealand.

Reports

O’Fallon, C., Sullivan, C. (2009). Trends in older people’s travel patterns: Analysing changes in older New Zealanders’ travel patterns using the Ongoing NZ Household Travel Survey. Wellington: New Zealand Transport Agency. Research Report 369 (pdf)

O'Fallon, C. & Sullivan, C. (2009). Trends in older New Zealanders' travel patterns. Presented at 31st Australasian Transport Research Forum, Auckland, October 2009. Paper (pdf)