Assessing the Impact of Parking Pricing on Transportation Mode Choice and Behavior
- Author(s): Ng, Wei-Shiuen
- Advisor(s): Deakin, Elizabeth
- et al.
This dissertation examines the impact of parking pricing on travel demand and behavior, using the University of California (UC), Berkeley campus as a study site. Parking pricing is often implemented to recover costs or to serve as a source of revenue for cities or private parking operators. However, parking pricing can also be an effective transportation demand management tool. Parking price can be set at market rates or can be set to meet other objectives, such as reducing emissions or traffic. In either case, by increasing the direct cost of driving, parking pricing can lead travelers to shift to public transportation or non-motorized modes. Parking pricing can also help to reduce total distance traveled through cruising reduction, and through trip reduction or consolidation, and in so doing can decrease congestion, air pollution and other transportation externalities. Understanding the role of parking pricing in influencing travel demand and behavior is crucial for determining whether a flexible and variable pricing structure can be effective in managing parking demand and scarce land resources, yet at the same time, generating adequate economic revenue.
The main objective of this dissertation is to analyze whether and to what extent changes in parking policies can alter transportation mode choice and parking preferences given different travel constraints, options and needs. Changes in parking policies examined in this dissertation not only include price, but also payment type (i.e. monthly, daily, or hourly), proximity of parking location to workplace and other incentives bundled together with specific parking options. Therefore, parking preference is defined as the pricing type and location of the chosen parking space. The types of parking pricing analyzed in this dissertation include paying by month, day, or hour, together with transit incentives bundled with different types of parking pricing options, while parking location is broadly divided into on-campus and off-campus parking. In order to better evaluate the impact of parking pricing and other transportation policies on travel behavior and demand, it is also necessary to understand how travel and parking behavior can be influenced by employment type and its respective flexibility of work schedule. In addition to accounting for the socioeconomic characteristics of the employees, this dissertation therefore investigates their job characteristics and the flexibility of their work schedule, both of which affect transportation mode choice and parking location because of their effects on time of travel, time, duration of stay at the workplace and frequency of commute trips.
The UC Berkeley campus was selected as a study site to reevaluate current parking policies and to improve parking pricing to lower transportation demand and to reduce cruising for parking. The University is situated adjacent to the City of Berkeley's downtown, in the inner suburban ring of the San Francisco Bay Area. The campus is served directly by several AC Transit bus routes and a Bay Area Rapid Transit (BART) station. UC Berkeley is one of the largest employers and trip generators in the region, with more than 36,000 students, 1,377 faculty members, and more than 12,000 non-academic staff. As a result, it generates more than 50,000 trips per day, whereas there are only approximately 5,000 parking spaces available on campus. There is a clear constraint on parking availability and transportation demand management tools are vital in maintaining a relatively low driving mode share. Current parking policies are designed to cover current operating costs, but fall well short of replacement costs, with an annual budget of approximately $13 million, except for bond payments. Furthermore, there is a wide range of employment types, job levels, work schedules, residential locations, and socioeconomic characteristics at UC Berkeley, which reflect varying employee attitudes, commute and parking choices. Therefore, findings from this dissertation can be applied to other regions.
UC Berkeley students are excluded in this study. Campus parking regulations restrict parking permits to students who live off campus at a distance of two miles or more, and only 26 percent of students meet this criterion. As a result, only eight parking lots or garages are available for student parking. The study focuses instead on faculty and staff transportation demand and parking behavior.
A total of four different research methods were used to investigate attitudes and behavior, namely, open-ended interviews, focus groups, a transportation and parking survey, and discrete choice analysis. The combination of quantitative and qualitative methods provides complementary yet independent observations, as each method examines different facets of the research question. The survey was designed to examine current transportation demand and parking behavior, as well as potential changes in behavior under various parking pricing scenarios. Hence, it was used to collect both revealed preference (RP) and stated preference (SP) data.
In-depth one-on-one interviews were conducted with a total of 86 UC Berkeley employees. The open-ended interviews were designed to understand the linkages amongst travel and parking behavior, work schedule and employment type. The purpose of interviewing is to understand the valuable lived experience and actions of a small sample of UC Berkeley employees, to gain a clearer perception of their current travel behavior, habits and preferences. An additional 10 focus groups with eight faculty members and 105 staff members were then conducted, prior to the final execution of the survey. Focus groups were used in this dissertation to allow a deeper understanding of the underlying reasons contributing to any potential changes in mode choice that cannot be captured by the interviews and survey alone. Findings from the interviews and focus groups were then incorporated into the final transportation and parking survey. The online version of the survey was mailed electronically to all campus faculty and staff members (approximately 12,000 employees) in December 2013, with a response rate of approximately 30 percent (n = 4,188). Data collected from the survey were used to develop multinomial logit (MNL) models for mode choice and parking choice. A RP-SP joint analysis was also conducted for the transportation mode choice model.
Together, these research approaches illustrate current travel behavior and parking preferences. The also help determine the role of parking pricing in shifting transportation mode and parking location choices, show the differences in travel behavior and parking preferences according to University affiliation and provide insights into future UC Berkeley parking policies, as well as for other campus communities.
Results from this study show that a considerable number of employees (23 percent) use a combination of various modes when commuting to campus, while others rarely switch to something other then their most preferred mode (77 percent). Most regular users of transit or non-motorized modes would drive occasionally too, with driving frequency ranging from once or twice a week to a few times a year. Employees who drive alone to campus are categorized by their frequency of car use in this dissertation, i.e. regular drivers, regular but flexible drivers and occasional drivers. Results show that regular drivers drive every day of the workweek mainly because of convenience, comfort, safety, low transit accessibility, and having dependents. Regular but flexible drivers live in residential locations without the availability of comparable transit services, or where biking or walking to campus is not a feasible option. However, they would use transit if services have improved or other transportation modes and not drive if they could. Hence, they are more flexible than regular drivers in terms of their driving frequencies and mode choice. They tend to not have any dependents and have arrival and departure times that are not affected by someone else's schedules. Lastly, occasional drivers are employees who have multiple transportation options and they could either be more cost sensitive or prefer to use transit or non-motorized transportation modes for other non-cost related reasons. In both cases, occasional drivers drive to campus under special circumstances, such as being late for work, bad weather, having to carry bulky and heavy belongs, or having to attend certain events after work.
Results from the survey show that more employees in higher household income categories drive to campus than employees in lower income groups. Carpool and biking are two transportation mode choices that are not affected by income, as there are no substantial differences in the percentages of employees who carpool or bike across all income categories. On the other hand, the number of employees who use the bus is significantly higher for lower income groups than higher income groups and walking as a primary mode choice is most common for the lowest and highest income categories. Any changes in parking pricing on campus will tend to affect medium income groups the most.
Work schedule and employment type have been found to affect parking location more than transportation mode choice. Driving alone is the most popular choice amongst all University affiliates and job categories as found in all three data sources, i.e. interviews, focus groups and survey. In general, almost half of the respondents drive alone to campus (49 percent), followed by transit (23 percent) and non-motorized transportation modes (16 percent). The remaining respondents carpool (seven percent), ride motorcycle (one percent), or use other forms of transportation, including being dropped off (four percent). However, not all University affiliates who drive have the same parking location preferences. Approximately 30 percent of employees who drive choose to park at of-campus parking locations. The flexibility of work schedule, which is directly related to employment type or University affiliation affects where an employee chooses to park more than transportation mode choice. Arrival and departure times, the number of hours spent on campus per day and the number of days on campus can all influence the parking location or parking type chosen. Lower income groups have been found to park less on campus than higher income groups. Changes in parking pricing are most likely to affect the parking location of employees with flexible work schedules more than their mode choice. Hence, employees who currently drive alone to campus will continue to do so, but may choose to park at a different location from where they currently park if parking prices are increased.
Results from the mode choice models show that the respondents prefer alternatives with lower travel cost and time and that flexibility in work schedule may not decrease drive alone mode share. Staff members tend to prefer driving and parking on campus more compared to faculty members, while female respondents drive alone and park on campus more than male respondents do. Older employees with higher household income also prefer driving and parking on campus compared to younger employees and employees with lower household income.
The average minimum annual salary at UC Berkeley is approximately $65,000 or $34 per hour. Comparing this value with the value of time estimates from the MNL models, it was found that the RP value of travel time of $16 per hour is 47 percent of the minimum average hourly income. The value of travel time is not surprisingly the lowest for low income respondents ($14 per hour) and the highest for high income respondents ($18 hour).
The parking choice model shows that a daily parking payment is the most preferred parking option. The greater the parking fee refund and the availability of free transit passes, the greater the utilities of the monthly parking permits. When the transit pass also includes BART, it increases the utilities of the parking options. Survey respondents find parking options with shorter walking time more attractive and the longer an employee stays on campus, the greater the preference to drive and park on campus. Faculty members are less likely to choose a monthly parking permit than staff members. However, it is important to note that adjunct professors and other non-professor titled academic staff are included in the "faculty" category in the discrete choice analysis.
The value of walking time from parking location to workplace is slightly lower at $15 per hour. The value of walking time shows that employees are willing to spend $0.25 to park a minute closer to their primary workplace on campus. Walking distance is thus a significant factor in influencing parking choices, in addition to parking costs and should be considered when pricing future parking facilities.
The findings of this dissertation show that parking pricing plays an important role in regulating transportation demand by shifting mode choice, especially in a campus environment, where the majority of the employees who drive park on campus. However, it has a greater impact on influencing parking location, which can lead to changes in parking revenue for the University. Unlike existing studies, this dissertation examines the impact of parking pricing with the consideration of various payment type, parking location, transit incentives, flexibility of work schedule, income, and the willingness to walk from a parking space to the final destination. The use of qualitative research methods to complement results from a discrete choice analysis has also provided further insights to transportation mode choice and parking behavior.