Hear Vij talk about his research on the peak car phenomenon.
The turn of the twenty-first century has been witness to stagnant or declining levels of car use across much of the developed world, a process referred to in the popular media as the ‘‘peak car” phenomenon. In the United States alone, between 2000 and 2012, car sales went down by 17.5%, per capita highway passenger vehicle miles traveled (VMT) decreased by 5.1%, and the proportion of the driving age population that is licensed to drive declined from 88.0–85.2%. Similar trends have been observed across other parts of the developed world, including Australia.
Some studies have ascribed the reversal in car dependence to changes in traditional economic factors that include a recessionary economy and rising oil prices. Some have attributed the phenomenon to equally important social changes, such as an ageing population, rising higher education enrollment rates, an increase in the average age of entry into the labor market and the decision to start a family at a later age. Others have argued that these trends cannot be explained purely in terms of economic and social factors, but are reflective of additional shifts in underlying lifestyles, attitudes and preferences towards the car.
A recent study by Dr. Akshay Vij from the Institute for Choice, in collaboration with Sreeta Gorripaty and Prof. Joan Walker from the University of California, Berkeley, examines changes in observable patterns of travel mode choice behavior in the San Francisco Bay Area, United States between 2000 and 2012, and attempts to explain these changes in terms of possible shifts in latent modal preferences, such as the willingness to consider different travel modes and the willingness to pay for access and use of the same, while controlling for the confounding influence of concurrent changes in the socioeconomic environment and the transportation infrastructure.
Their findings indicate that shifts in latent modal preferences exceed analogous changes in observable travel mode choice behaviors. For example, private motorized vehicle mode shares decreased from 85.0% in 2000 to 81.2% in 2012, but the proportion of the population that only considers private motorized vehicles when deciding how to travel is found to decline from 41.7% to 23.5% during the same period.
Changes in economic and social factors and changes in the level of service of different travel modes are found to have had a marginal effect. Had modal preferences not changed between 2000 and 2012, over and above changes in the socioeconomic environment and the transportation infrastructure, their study finds that private motorized vehicle mode shares would have increased to 88.3% by 2012.
Finally, shifts in modal preferences are not found to be limited to any one generation but to have cut across the entire population, reflecting broader cultural shifts that have transcended generational differences between Baby Boomers, Gen X and Millennials.
The study adds to a growing body of literature that has contended that travel preferences may change over time, in excess of changes in the socioeconomic environment and the transportation infrastructure. By offering greater insights on how preferences have changed in the past, the proposed framework lends a basis for extrapolating how preferences might change in the future, and what the implications might be for observable patterns of travel and activity behavior.