We present a discussion about how socio-demographic factors affect the demand for personal land travel.
Socio-demographic is a convenient adjective that we use to cover primarily demographic factors, plus their interaction with employment and income. Other factors such as urbanisation and new technologies are also briefly discussed.
We look primarily at overseas literature on various theories that per capita demand for travel has peaked and/or shifted modes, and at the evidence for and against these theories. Local literature on this topic is scarce so we decompose New Zealand data on travel by private vehicle, finding that socio-demographic factors can explain most of the changes in private vehicle travel since 1998.
We also use a model that was specifically designed to project New Zealand travel demand to explore the effects of socio-demographic factors on private travel. Most scenarios project continued growth. Rates of growth do slow, however, and in some regions private vehicle travel per capita declines.
The results demonstrate that interactions between social, demographic and economic factors, and their effects on travel demand, are complex.
Keywords: demographics, peak car, transport demand, saturation, technology, VKT