University campuses are challenged with offering commuters parking options that are sustainable, equitable, and flexible. In summer 2020, the Center for Advanced Hindsight and MoveVU at Vanderbilt University’s Mobility and Transportation Office piloted a new daily parking program aimed to reduce single-occupancy vehicle use and increase flexibility in parking options. The program allows users to pay for parking on a daily basis, rather than purchasing a monthly or annual pass, which can act as a sunk cost. By paying for parking daily, users may choose on some days to commute by transit, biking, or walking to save on parking costs.
A previous study conducted in collaboration with researchers at the London School of Economics found that commuters select more sustainable transportation options after viewing information that favorably orders choices such as transit, walking, and biking above the option of driving alone in terms of factors such as cost, sustainability, and duration. Building on these findings, researchers worked with MoveVU to investigate how message framing could influence program sign-ups.
To assess whether message framing impacts commuters’ willingness to use the daily parking program, we emailed 12,000 Vanderbilt University students, post-docs, faculty and staff an invitation to join the daily parking pilot. The daily parking option gave participants the ability to pay for parking in designated spaces only on the days they drove their vehicle to campus. The other option provided was an annual parking permit which allowed drivers to park in all non-reserved spaces on campus at any time during the academic year.
Email recipients were randomized into 4 conditions:
- Control – received an email presenting all parking options, including the daily parking option.
- Daily First – received an email presenting all parking options with the daily parking option listed first and the annual parking permit listed second.
- Financial- received an email presenting all parking options and highlighted the daily parking program’s potential financial benefit.
- Environmental- received an email presenting all parking options and highlighted the daily parking program's potential environmental benefit.
Figure 1. Excerpt of Control Group parking email compared to Favorable Ordering email. The Daily First email uses favorable ordering by listing the daily parking permit option before the annual parking permit option.
Figure 2. Excerpts from the Financial Impact and Environmental framed emails. Financial and Environmental are included in the email subject line and bolded in the body of the email. Both emails list the daily parking option before the annual parking permit option.
A total of 1,579 people submitted an interest form for the daily pricing program. We found that in comparison to the control group, the financial-framed email yielded the highest percentage of daily parking program sign-ups and was statistically significant. While not statistically significant, we found that the favorable ordering and environmental impact emails also demonstrated a slight increase in program sign-up rates.
Figure 3. Program sign-ups percentage by condition.
Why It Matters
The results from this study provide a base understanding of how message framing can influence drivers to select new parking options. As the need to provide more sustainable commuting options increases, it is important to understand what may influence drivers’ commuting choices. Providing options such as a daily parking permit allows permit holders to be more mindful of the days that they are driving to a specific destination. A daily parking permit means that each decision to drive will come with a price. In comparison, it is difficult to conceptualize the daily rate for an annual permit and the sunk cost associated may lead to increased driving in order to “get your money’s worth.” Daily payments prompt commuters to consider sustainable alternative transportation options such as carpooling, walking, public transit, or biking.