THE CURIOUS CASE OF REDUCING AUTOMOBILE USE

by Ram M. Pendyala, Arizona State University and Chandra R. Bhat, The University of Texas at Austin

There is a lot of interest in, and emphasis on, trying to motivate people to shift to alternative and more sustainable modes (means) of transportation for their travel as nations attempt to reduce greenhouse gas emissions, render communities more sustainable and livable, and combat ill effects of climate change. The latest bipartisan infrastructure bill has hundreds of billions of dollars of investments aimed at enhancing transit, bicycle and pedestrian transportation networks, implementing strategies to better manage and reduce automobile traffic, and motivating the traveling public to eschew the use of the automobile for daily travel. Policymakers and the public alike are counting on these investments and strategies to deliver a more sustainable mobility future. 

With the nation getting ready to invest hundreds of billions of dollars from the infrastructure bill to expand sustainable transportation modes in the hope that this will naturally draw travelers out of their cars, it is absolutely imperative to understand that these investments and strategies – by themselves – are unlikely to yield results anywhere close to what policymakers and public envision and seek to achieve. In fact, historical evidence to date suggests that it has been stubbornly difficult to realize any substantial decrease in vehicle use, with decades of attempts at doing so (through a variety of investments, programs and strategies) proving largely futile. Despite all of the efforts being made to stem the tide of automobile use, why does it continue to grow and be the dominant mode of transportation (particularly in the US)? As experts in traveler behavior and values who have studied for three decades how and why people make the mobility choices that they do, we have applied advanced statistical analysis techniques to try and answer this question.

In our recent study titled “The Influence of Mode Use on Level of Satisfaction with Daily Travel Routine: A Focus on Automobile Driving in the United States”, we find that the aspirations of planners and policymakers to reduce private vehicle use are unlikely to be realized unless investments in, and incentives promoting the use of, alternative modes of transportation are combined with aggressive measures to penalize automobile mode use for daily travel.  The research study aimed to determine the extent to which the relative use of the auto-driving mode for daily travel affected the degree of satisfaction that people derived from their daily travel routine.  The common perception is that people dislike driving and experience a lower quality of life when they are dependent on the automobile for their daily travel.  If only we provided alternative modes of transportation with a high level of service, then people would shift in droves to more sustainable modes of transportation.  However, that would be true only if the original premise, that automobile use and dependency contribute to a lower quality of life, were also true. 

To verify the validity of the original premise, we conducted a survey to understand how people travel and how satisfied they are with their daily travel routine.  The survey was conducted in the four metropolitan regions of Phoenix, Austin, Atlanta, and Tampa.  Through a very sophisticated statistical analysis that controls for many factors, we find that the data do not support the premise that automobile use is associated with a lower quality of life.  We find that people with higher levels of relative amounts of driving are actually more satisfied with their daily travel routine, essentially explaining why decades of efforts aimed at trying to get people out of their cars and into more sustainable alternative modes of transportation have proven utterly futile in most contexts in the United States and around the world. 

This essentially means that two conditions have to be met for any significant shifts in mode use to occur; first, we must provide transportation alternatives whose levels of service are super-competitive and comparable to the automobile (in the vast majority of contexts, this is extremely difficult to achieve in the absence of prohibitively massive investments of resources in transportation alternatives), and second, we must disincentivize the use of the auto driving mode in very significant ways through restrictive and punitive measures such as tolls and fees, parking restrictions, and limited roadway capacity. Satisfying both of these conditions is obviously very difficult, both from a financial and a public acceptance standpoint. 

We posit that greater progress in reducing vehicle use can be realized through coordinated land use – transportation planning that promotes high density, mixed-use developments characterized by walkable and transit- and bicycle-friendly environments.  And the carbon footprint of personal automobile travel can be reduced through an aggressive campaign to accelerate transportation electrification, with the adoption of electric vehicles enabled by incentives and the widespread deployment of electric vehicle charging infrastructure. Hence, we suggest that any plans to curb automobile use and the associated emissions footprint incorporate both a strong land use element and an effective transportation electrification advancement strategy – to break from historical trends that have been characterized by an unbridled increase in automobile travel.  

We acknowledge the significant work and contributions of the study co-authors including: Tassio Magassy and Irfan Batur, both of whom are doctoral students and graduate research associates at Arizona State University; Aupal Mondal and Katherine Asmussen, both of whom are doctoral students and graduate research associates at The University of Texas at Austin; and Sara Khoeini, who was an Assistant Research Professor at Arizona State University when the study was conducted.  The study was partially funded by the US Department of Transportation through its University Transportation Centers program. 

Article details

Influence of Mode Use on Level of Satisfaction with Daily Travel Routine: A Focus on Automobile Driving in the United States.
Tassio B. Magassy, Irfan Batur, Aupal Mondal, Katherine E. Asmussen, Sara Khoeini, Ram M. Pendyala, Chandra R. Bhat.
First Published: May 31, 2022
DOI: 10.1177/03611981221088199
Transportation Research Record: Journal of the Transportation Research Board