Depending on a car could be impacting your life satisfaction

A viral research study led by Rababe Saadaoui, a PhD planning student in Arizona State University's School of Geographical Sciences and Urban Planning, has uncovered a link between car dependency and life satisfaction in the United States.

Saadaoui's research team of ASU colleagues included Associate Professor Deborah Salon, Assistant Professor Huê-Tâm Jamme, PhD planning student Nicole Corcoran and Jordyn Hitzeman, a Flinn Scholar from Barrett, The Honors College.

“This research comes from my interest in how we can plan and design cities that promote health and well-being. One question that particularly intrigued me is whether the reliance on cars — something so central to how people get around in the U.S. — contributes to greater happiness or if it detracts from our overall life satisfaction,” Saadaoui said.

By analyzing data from a national survey of 2,155 U.S. adults living in urban and suburban areas, the study found a significant link between car dependence and life satisfaction. The research revealed that when individuals relied on cars for more than 50% of their out-of-home activities during a typical week, their satisfaction with life declined. These findings highlight a critical threshold, showing that excessive car dependence, beyond a certain point, is associated with lower life satisfaction.

The findings suggest planners and decision-makers should promote multimodal transportation such as walking, biking, public transit and cars, along with land-use strategies to reduce car dependence. Moreover, it underscores the importance for urban planning and transportation policies to support these options to lessen reliance on cars and improve life satisfaction.

ASU News spoke with Saadaoui to learn more about the results of this study and how its findings can inform future urban planning efforts through multimodal transportation options.

Question: Could you elaborate on the "threshold effect" regarding car dependence, specifically how relying on a car for more than 50% of out-of-home activities in a typical week is linked to a decline in life satisfaction?

Answer: One way we measured car dependence was by asking respondents to estimate the percentage of time they rely on a car for out-of-home activities in a typical week. What we found is that, generally, as car dependence increases, life satisfaction tends to go up — but only to a certain point. Beyond that, we start to see a decrease.

To make sure the relationship we observed was not influenced by other factors, we used regression analysis and controlled for various external factors that other research has linked to life satisfaction. The tipping point, or threshold, where life satisfaction begins to decrease, is around 50%. When people rely on their car for more than half of their out-of-home activities, it seems to have a negative effect on their life satisfaction.

Q: What do the findings suggest about why life satisfaction is lower at both very low and very high levels of car dependence?

A: It is not surprising that life satisfaction is low at lower levels of car dependence. In the U.S., where most cities are built around car use, not having a car or using one very rarely can limit mobility. Since alternative transportation modes are not always an option, this lack of mobility can negatively affect life satisfaction.

What is more interesting is that life satisfaction also tends to drop at high levels of car dependence. When people become overly dependent on their cars, the benefits that cars typically provide tend to diminish. This can happen for a few reasons. For example, excessive car use often leads to less physical activity, which is associated with many health and well-being challenges. Car dependence can also reduce social interaction, which is important for well-being. Spending time in traffic can be stressful and frustrating. There is also the financial side — maintaining a car, paying for gas, repairs and parking can take a toll on life satisfaction.

Q: How might physical health and activity influence the relationship between car dependence and life satisfaction?

A: While we did not specifically explore the relationship between car dependence and health, other studies suggest that overreliance on cars may lead to a less active lifestyle, which is something that alternative modes of transport like walking or biking can help address. Given the benefits of physical activity for overall well-being, it is likely that reduced activity associated with high car dependence could contribute to lower life satisfaction.

Q: Did your study uncover any surprising findings about the link between car dependence and life satisfaction, or findings that contradicted existing research on travel satisfaction and related emotions?

A: We found a stronger relationship between car dependence and life satisfaction than previous research has suggested. Many studies have focused on how car use impacts travel satisfaction and emotions during trips, which are typically short term and more temporary.

However, what we observed is that car dependence does not just affect how people feel while traveling — it seems to have a more lasting impact on overall life satisfaction. This finding is surprising because existing studies often display a weak link between car use and broader life satisfaction. Our research suggests that the effects of car dependence go beyond the immediate experience of a trip and may influence long-term sense of well-being.

Q: How does this study address the fact that many Americans rely on cars due to land-use patterns favoring car-based mobility, and how can multimodal options help reduce this dependency?

A: Most Americans choose to rely on cars because they enjoy driving, and for many it is simply a habit that is ingrained in daily life. However, car dependence is not a choice for others. Many cities in the U.S. are designed around car use. Historically, land use patterns and policies have left people with less alternatives. Our study suggests that when people rely on cars for more than half of their out-of-home activities, it can negatively impact life satisfaction. This highlights the importance of promoting multimodality. When people are offered a range of transportation options, they can choose what works best for their needs, which could help reduce car dependence and mitigate potential negative effects on life satisfaction.

Q: What role can planners and policymakers play in promoting multimodal transportation options — such as biking, transit, ride-sharing and micromobilities — to help people drive without exceeding moderate levels of car dependence?

A: Planners and policymakers have an important role to play in promoting multimodality. While some progress has been made, there is still more to do. By continuing to integrate diverse transportation options, including public transit, ride-sharing and micromobilityTransportation using lightweight vehicles such as bicycles or scooters. , we can provide people with more ways to get around. Well-connected networks and areas designed for walking and biking make these options more accessible. Policies that encourage compact development, car-free neighborhoods and mixed-use areas can also help reduce car dependence. These steps can help people stay less dependent on cars, supporting sustainable travel while improving health and well-being.