TCRP Report 123: Understanding How Individuals Make Travel and Location Decisions: Implications for Public Transportation
The purpose of this project (TCRP H-31) is to explore a broader social context for individual decision making related to residential location and travel behavior. Because residential location and travel behavior have a large effect on society’s consumption of energy, on levels of pollution, and on health, there is great value in increasing our understanding of the mechanism of choice. Better understanding could lead to better insights on the part of planners and decision makers as to how to predict choice and how to influence it through better policies and design, education, and communication. While the transportation community has considerable experience in using rational economic models of decision making in exploring residential and travel choice, there is less research into decision-making models from other fields, such as sociology, psychology, and marketing research. This project provides a look at an approach from the field of psychology that adds valuable perspective to understanding behavior.
Although the work done for this project used a different methodology for analysis, the project also had a goal of deriving practical implications and policy guidance for encouraging more use of public transportation and walking. An underlying assumption is that growing urban congestion and impaired mobility can be mitigated by encouraging people to substitute public transportation and walking for individual automobile use. A related assumption is that if people live in communities that are transit oriented (called compact neighborhoods in this research), they will walk and take public transportation more. A practical challenge is, of course, how to promote this kind of behavior in enough instances to have a measurable, beneficial effect on travel conditions. The premise of this research is that by gaining a better understanding of the links between individuals’ attitudes, intentions, and behaviors with regard to compact neighborhoods and travel alternatives to the automobile, strategies can be better configured and targeted to help achieve the desired outcomes.
Thus, the goals of this research are twofold: namely, to improve understanding of how people make travel and location decisions, and to derive practical implications and policy guidance for encouraging more use of public transportation and walking. Given the goals of the research, a number of overall objectives have been set, as follows:
- Explore the characteristics of market sectors that are more likely to be favorable to an urban residential environment, particularly an environment characterized as a transit oriented development (TOD) or, as used in this research, a compact neighborhood.
- Explore the characteristics of market sectors that are more likely to be favorable to increased transit use and walking.
- Explore the impact of neighborhood type on the use of transit and walking.
- Explore methods for encouraging more walking and transit use.
- Explore the theory of planned behavior (TPB) as an approach to understanding how individuals make travel and location decisions. In particular, explore TPB in the context of a decision to move to a compact neighborhood and to take environmentally friendly modes, such as walking and transit.
- Examine the power of the TPB to distinguish these market sectors and provide insight into motivating factors.
This project follows on the successful “New Paradigms” TCRP research program, which examined new structures and approaches for transit agencies (1). One motivation for this follow-on work was to look at new approaches from other fields, such as psychology and social marketing, for motivating individuals to choose transit and transit-friendly communities.
This research included an extensive review of the literature and interviews with experts in a variety of related fields. A conclusion from the literature and interviews was the value of applying the TPB in an examination of individual decision making for residential and mode choice. Using the TPB, the project team has conducted an extensive amount of original research over a 3-year period using focus groups and Internet panels. The research has yielded some interesting findings, provided new data for existing research issues, and left plenty of questions to be explored with further research.
Practical Implications from the Research
This project included the use of Internet panels derived from large metropolitan areas in the United States where there is good transit service. Separate surveys were used to query respondents’ attitudes and intentions about using transit and walking and to query their attitudes and intentions about moving to a compact neighborhood. Although the research was focused on testing new methodological approaches, there are some findings that provide practical advice to practitioners in the transit field. Most of the following findings are based on analysis of the Internet panel surveys.
Implications from the Research on Mode Choice
Findings from the research on mode choice that have practical implications include the following:
- Although respondents indicated that transit service was within walking distance for most of them (70%), normative support for increased walking and use of public transit was low. These individuals said they wanted reliable transportation at low cost, and they didn’t want to spend any additional time commuting, nor did they want to be dependent on someone else for their transportation. They believed that transit would take them more time and they would have less ability to control the timeliness of their arrival. They also expressed a need to use a car for short or spur-of-the-moment trips or to carry heavy things. These attitudes present a challenge for policymakers seeking to encourage more transit ridership. Replacing the car will take a suite of services to meet requirements for both speed and flexibility.
- When respondents were asked to consider traditional marketing messages and a suite of transit supportive services (including good downtown transit service, regional transit service, smart card, shuttle service, smart phone, and car sharing), their beliefs about transit changed. However the changes were apparently due to the suite of services and not to the marketing messages. The practical implication is that it will be difficult to significantly change beliefs toward transit riding with public policy messages alone. More emphasis wineed to be placed on supplementing messages with a suite of services that enhance the overall transit riding experience.
- Being able to depend on transit to “get me to my destination in a timely way” was a key driver of attitude. Providing information to customers on transit schedules and improving the reliability of the service would appear to be key strategies based on this research.
- Although those respondents that were concerned about reducing pollution and improving health had a more positive attitude toward walking and taking transit, respondents were not convinced that the suite of transit supportive services would reduce pollution and improve health. A message about the positive health and environmental impacts of transit use also was not convincing. There is a need to more convincingly communicate the positive health and environmental impacts of walking and transit.
- Respondents’ attitudes toward transit riding and walking are the most critical drivers of intentions to increase use of these modes, but respondents’ self-confidence in using transit and walking and their perception of others’ opinions also affected their intentions. In this research, respondents’ attitudes did not change even with the messages and transit-supportive services. Although attitudes did not change, respondents’ self-confidence that they could take transit increased when additional transit-supportive services were considered. Also, they believed that their families would be more supportive of their taking transit and walking. This would suggest that a practical policy approach would be to seek to provide and market a set of ancillary services intended to make transit riding more simple and attractive (a higher status activity) for those who otherwise are inherently reluctant to use transit.
- Respondents’ concerns about being stranded when using transit appeared to be the most critical driver of their self-confidence in being able to take transit as well as in the approval of friends and family. This was especially true of the environmentally oriented market segment, which was willing to change modes if the conditions associated with transit riding were improved. The practical policy implication is to focus on providing this group, in particular, with ancillary services that can help them overcome these kinds of concerns. By making the transit system safer and more attractive, family and friends are likely to feel more positively about transit and further motivate the members of this group to translate their expressed intent into actual transit riding behavior.
- Prior research has shown that an impediment to using public transportation is that the behavior is unfamiliar to many people and hence is not actively considered as an option. This research verified the importance of respondents’ self-confidence in using public transportation. Many communities and employers are offering incentives for people to try out transit, including free passes, employee discounts, or charges for parking personal cars at work, especially for single-occupant vehicles. These actions will help transit to become more familiar and increase users’ self-confidence in taking transit.
Implications from the Research on Compact Neighborhoods
Findings from the research on compact neighborhoods that have practical implications include the following:
- Some features of a compact neighborhood were of greater importance to this sample of respondents than other features. The most important belief was that it would be easier to get to stores, restaurants, libraries, and other activities if one were living in a compact neighborhood. Developers of compact neighborhoods should ensure that they are near interesting destinations such as stores, restaurants, and other activity centers.
- Making new friends with close neighbors in a compact neighborhood emerged as an important influencing factor, along with needing fewer cars and liking having public transportation readily available for the places you want to go. Marketing campaigns intended to promote the values of living in compact neighborhoods should emphasize these kinds of attributes and benefits.
- Individuals who believed that such a residential move would result in more street noise or less living space had a more negative attitude toward the move. Practical efforts to promote living in compact neighborhoods should be aimed at countering these perceived negative attributes and emphasizing the positive attributes.
- Individuals are more likely to feel they could move to a compact neighborhood if they could find affordable housing. This was the most important perceived barrier to such a move, over others that included having to get by with fewer cars, having less living space, or losing touch with current friends. Public policy that seeks to ensure the availability of affordable housing in compact neighborhoods would be indicated by this finding.
- Respondents who expressed a more positive attitude toward living in a compact neighborhood are the best initial candidates for promotional efforts. It would make most sense to approach those with the highest probability of receptiveness to campaigns that encourage transit use and walking, as well as living in compact neighborhoods. For example, those who say that owning fewer cars is a good thing would fall into this positive group, as would those who value a clean environment.
- If family and friends are supportive or encouraging of a move to a compact neighborhood and communicate that riding transit and walking reflect appropriate values, then an individual is more likely to be motivated to do those things. Promotional efforts could be directed toward families, rather than just toward individuals, to help build a foundation of support for the value of living in compact neighborhoods and using public transportation. In the longer term, seeking to influence community normative values with respect to these behaviors could have positive effects on an even larger segment of the population.
- From a practical policy standpoint, perhaps the biggest impediment to marketing compact neighborhood living and use of transit is the pervasive reluctance to give up personal automobiles. This research showed that the average number of automobiles per person in a household is more predictive of the propensity to walk and use transit than the type of residential neighborhood or set of urban/environmental values held by the individual. Policies such as reducing the zoning requirement for parking in compact neighborhoods, providing mortgages that recognize savings from reduced car use or ownership, and employer incentive programs for transit use and ridesharing could help in this regard. However, such measures need to be accompanied by substantial improvements in transit and walking services and amenities, such as those described in the findings presented here. At the same time, policy to create new infrastructure to facilitate walking and transit will be more successful if it is coupled with efforts to support and encourage reduced auto ownership.
- Prior research on the propensity to change modes suggests that people are creatures of habit. Individuals who have never used public transportation or who use it rarely tend not to consider public transportation as a viable alternative to meeting their transportation needs. The times when these individuals are most likely to consider such a change in transportation mode is when they are making lifecycle changes, such as a change in residence or a change in employment. Thus, practical strategies that seek to induce a mode change should recognize that individuals may be more receptive during these periods of change in their lives.
Summary of Implications for Transit Managers
Figure S-1 highlights some of the practical strategies that may be undertaken in an effort to promote living in compact neighborhoods and encourage more transit use and walking, as suggested by the research findings from this study. Practical implications of this research all derive from three component strategies for accomplishing the goals of the research, which include encouraging individuals to move to a compact neighborhood and encouraging them to increase their use of transit and walking in place of automobile use. These component strategies are as follows:
- Encourage policies that lead to the creation of urban form that is highly conducive to transit use and walking. Attributes of compact neighborhoods include ease of walking to stores, restaurants, and other activities; easy access to public transportation; ability to live with fewer automobiles in the household; and opportunity to interact with neighbors. Work through employers and community policymakers to provide incentives for transit use.
- Provide a set of services that complement and support using public transportation, particularly for the market segments with the most potential to increase transit use. These include providing real-time information about transit arrival/departure times, as well as other services that make people feel safer and more confident about using transit.
- Educate and market the use of public transportation to the public, focusing first on segments of the population that are known to be more receptive. Focus marketing and policies on increasing the status of transit and making it simpler to use.
As pointed out in this research report, there are many challenges to accomplishing the desirable practical outcomes discussed in this summary. It is also clear that additional research will be needed to more fully understand the factors that link attitudes and values with the outcome behaviors. The positive market sectors identified in this research represented 30% to 45% of the sample, and practical strategies noted above should target those segments first. The promotional messages directed to these individuals will need to be tailored to their needs and matched with their attitudes and values, as identified herein. However, no one approach is likely to be highly successful on its own; rather; a variety of approaches must be applied simultaneously, including creating conducive urban form, providing supportive public services, and coordinating these with targeted marketing and promotion. In addition, a suite of incentives and disincentives should be added, resulting in structural, social, and economic forces that may be expected to have a reasonable chance of changing human behavior in ways favorable to usage of public transportation and walking.
The Theory Behind the Research: The Theory of Planned Behavior
The model of human behavior used in this research is the TPB, as illustrated in Figure S-2. This model, which comes from the field of psychology, holds that human action is guided by three types of considerations:
- Attitude toward the Behavior—An individual’s own evaluation of an action, such as riding transit. It will be referred to as attitude.
- Subjective Norm—An individual’s perception of what others will think if he/she takes an action (e.g., what friends and parents will think if he/she rides transit).
- Perceived Behavioral Control or Self-Confidence—An individual’s assessment of his/her ability to take an action, such as taking transit.
For each individual, these three types of considerations will have different importance or weighting, depending upon the behavior or action. For example, young teens, as compared with older adults, may be more influenced by the opinions of their peers in a decision to take transit. Attitude, subjective norm, and self-confidence all contribute to an individual’s intent to carry out a behavior. Whether an individual actually carries out the intent depends also on his/her self-confidence in doing so.
Selection of the TPB as the model for this research followed a literature review that identified extensive use of the TPB in the health field. The literature review also found that the TPB has been applied in several European studies of mode choice.
The research approach for the above findings involved the use of focus groups and a consumer panel to investigate how individuals regarded (a) moving to a compact neighborhood and (b) increasing their use of public transportation and walking. In Phase 1, the purpose was to investigate the decision to move to a compact neighborhood, whereas in Phase 2 the purpose was to investigate the decision to increase use of public transportation and walking. The consumer panel was recruited by email and surveyed on the Internet.
The sample for the Phase 1 Internet panel was drawn from 11 major metropolitan areas, distributed across the United States, that offered public transportation services. Specifically designed for the transit industry, the sample is drawn from highly urbanized areas, such as New York, Chicago, Los Angeles, and Boston. Of the total sample, 639 were selected from a panel conducted by a commercially owned business, while 226 were drawn from a research panel maintained by New Jersey Transit.
The Phase 2 Internet panel was made up of 501 respondents drawn from the Phase 1 panel, with additional individuals added from the 11 major metropolitan areas. The surveys were specifically designed to oversample groups with proximity to good public transportation, and they were not intended to be representative of the national population.
The Positive Market Segments
Market segments were created for each project phase by grouping respondents based on their values and their attitudes toward moving to a compact neighborhood and making more trips by walking and using public transportation. In each phase, two positive segments were found—a transit-oriented market segment and an environmentally oriented market segment (see Chapters 7 and 11 for more detail). The characteristics of the positive segments follow.
Transit-Oriented Market Segments
The transit-oriented market segments currently exhibit travel behaviors that are environmentally friendly. They walk more and take transit much more than any of the other market segments. More than 60% of the respondents say that transit is their primary mode to work. They report the lowest need for a car to get where they need to go, and they do not think they are wasting too much time driving in congestion. They enjoy driving less than any other group. They are more likely to think they could live with fewer cars than any other group.
The transit-oriented market segments are characterized by their present use and understanding of public transportation services. More than any other segment, they are traveling to downtown, the traditional destination for transit services. They have less of a need for a car to get where they need to go than any other segment. For them, issues such as the safety of transit services or difficulty in paying the fare are not considered to be deterrents to using transit and therefore are not important to be solved with new products and services. This group tends to have a strong idea of what transit is, as well as how it can improve on doing what it presently does. Having frequent bus or train service is considered very important, and they want transit to serve their most frequent destinations. They have the highest intent to increase their use of public transportation and walking, but not because of additional supportive technologies and services. They are already intensive transit users.
The transit-oriented segments have a higher percentage of young people than the other segments. Consistent with this, they have lived in their present home for less time than any other group. As urbanites, they have the highest reported access to frequent transit and the best access to reliable taxis. More than any other group, they have a commercial district within walking distance. Their houses do not have significant amounts of parking or a large lot. Emotional commitment from these young people to their neighborhood is, however, somewhat low, as they have the lowest propensity to believe that others think their home and neighborhood is nice. Fifty-five percent of this group currently live in a compact neighborhood or are contemplating moving to one in the next 2 years. Although they are the market segment with the most potential to choose a compact neighborhood when they move, they are not necessarily loyal to continuing to live in an urbanized neighborhood.
Environmentally Oriented Market Segments
The environmentally oriented market segments are the oldest of the market segments. In terms of present modal behavior, the environmentally oriented would seem to have a long way to go before making a residential move and following that up with a transit-oriented travel pattern: this group chooses transit less for the work trip (20%) than any other group. More predictably, the group has the second highest walking trip rate, although with a walking rate far behind that of the transit-oriented group. Its trip lengths are the longest of any group.
Consistent with their name, this group is very concerned about the environment. In terms of values, the group has the highest propensity of any to place a positive value on reducing pollution by driving less, improving their health, meeting more neighbors, and reducing the time spent driving.
The environmentally oriented segments have the highest ratings of any group for concerns about global warming and climate change, for protection of the environment with more taxes, and for being more active in helping the environment. They are most likely to disagree with the statement that environmental concerns are overblown. They remember their environmental leanings from childhood.
After the transit-oriented market segment, the environmentally oriented segment has the highest intent to change modes to include more transit and walking. That intent to change modes increased more than for any other market segment when the group was presented with transit-supportive services and technologies. This increase was not due to a change in their attitude, as the group did not significantly change their opinion that using transit and walking would be more desirable, pleasant, or interesting. Rather, the change in intent appears related to an improvement in self-confidence and the subjective norm. The environmentally oriented segment emerged as the most optimistic about nearly every question asked that assumed all the new services and strategies were available for use. Among the positive responses, they thought they would save money, improve their health, reduce pollution, reduce the time spent driving, and find the new services dependable. With the new products and services, the environmentally oriented segment had the highest propensity to say that it would be easier to pay the fare, it would be easier to know when the train would arrive, and they would have less fear of crime or of being left stranded. They believed that with new services available it would be easier to use transit and walk more, and they believed that their family and others would approve.
The environmentally oriented group is suburban and quite satisfied with their neighborhoods. More of this group lives in single-family homes than any other group. Their lots are bigger, and they are more satisfied with the size of their lot than any other group. Their homes have the most parking and the most trees and bushes. They are happiest with their access to work/school and with the quality of biking. They have the highest belief that other people think their home and neighborhood are nice. This group tends to show the highest ratings for the attributes associated with urban life; they have the highest belief they should be spending more time walking, just to be healthier.
In spite of the level of contentment experienced, the environmentally oriented group seems open-minded about a change of lifestyle. The group is the oldest, and they have been living in their present home longer than any other group. They, more than any other group, think that they are wasting too much time driving in congestion. The group tends to have a positive expectation of the results of a move to a compact neighborhood; more than any other group, they think they would exercise more, make more friends, and find it easy to get to local destinations. With such a move, they could own fewer cars and get by with less living space. In short, they are optimistic that they could make the changes associated with life in a neighborhood supportive of transit and walking. This group has a high potential for moving to a compact neighborhood and making an environmentally friendly mode change.
The Negative Market Segments
There were three negative market segments based on values and on attitudes toward moving to a compact neighborhood. There were two negative market segments based on values and on attitudes toward walking and using public transportation more. With regard to moving to a compact neighborhood, the negative market segments were the Conflicted/ Contented group, the Low Expectations group, and the Anti-Environmental group. With regard to increasing use of public transportation and walking, the negative market segments were the Happy Drivers group and the Angry Negative group.
The Conflicted/Contented group has an intent to move to a compact neighborhood that ranks in the middle of the pack. This group is the most complex of the five market segments for moving. They rank their concern with environmental issues (e.g., global warming/ climate change) among the highest of any group, while at the same time reporting a level of auto dependence that is among the highest of any group. While they express their commitment to environmental change, altering their neighborhood to attain that change is not a desired option for this group.
Low Expectations Group
The Low Expectations group does not value the attributes of a compact neighborhood that are desired by those who value urban attributes. In general, this group expresses less hostility to environmental issues than does the Anti-Environmental group, but does not place a positive value on the things that might be expected to occur in a compact neighborhood, such as getting more exercise or even making more new friends.
The Anti-Environmental group has the lowest level of intent to move to a compact neighborhood. This group expresses its displeasure most specifically to the concept of environmental causes, thinking they are “overblown” and unnecessarily costing them money. They report the highest propensity to love the freedom and independence of owning several cars, and the highest propensity to need a car to get where they need to go.
Happy Drivers Group
The Happy Drivers group provided a middle ranking for concepts associated with a change in mode. For example, the group has a slightly higher than average ranking on the statement, “For me to walk and take public transportation more would be desirable.” However, this pattern of near-average support of statements related to mode change never translates into a top ranking on any key variable. The members of this group had the highest propensity to say that they liked to drive, with high scorings on the freedom and independence that comes from owning several cars.
Angry Negative Group
The Angry Negative group is characterized its low evaluation of just about every aspect of altering modal behavior and by the radically low intent of its members to alter their own transportation behavior. This is the most negative group towards mode change. This group emphasizes its auto dependency, with the highest propensity of any group to need a car to get where they need to go. In the scenario in which there is more reliance on transit and walking, this group has the lowest propensity to say they would reduce the time spent in driving. Two of the few exceptions to the most negative role come in two questions concerning worry about crime. This group reports less worry than some other groups about crime while using transit or while walking; perhaps they do not worry about it because they do not think about it, having no intention to use it. In addition, the group has the second highest belief that lowering the cost of transportation would be desirable.
Learning from the Theory of Planned Behavior
In Phase 1 of the research the respondents’ thoughts and opinions about moving to a compact neighborhood were investigated. The survey participants were told the following:
We are interested in your thoughts and opinions about moving to a particular type of neighborhood. The neighborhood has good sidewalks, a mix of housing types, shopping or restaurants within walking distance, and nearby public transit. You would be able to walk, bike, or drive to nearby shops, restaurants, pubs, and a library, but parking would be limited. You would be close to cultural events and entertainment. The neighborhood would be as safe as where you live today. Parking near your home would be limited to one car per household or street parking or you could rent a garage space. In this survey, we will call this a compact neighborhood.
The TPB says that intent to move to a compact neighborhood will be driven by attitude, subjective norm, and self-confidence in being able to move. The data from the Phase 1 research confirmed that there was a significant association between each of those variables and intent to move, with attitude being the most important.
Attitude toward moving was measured by respondents indicating how pleasant, desirable, and interesting such a move would be. Subjective norm was nearly as important as attitude. Subjective norm was measured by respondents’ indications whether family and friends would approve of such a move. The research confirmed that people care strongly about what others think of their neighborhood.
A more interesting question is, what characteristics of compact neighborhoods drive respondents’ attitude, subjective norm, and self-confidence? The key findings are as follows:
- The strongest association with a positive attitude toward moving to a compact neighborhood was the belief that it would be easier to get to stores, restaurants, libraries, and other activities.
- The belief that one would make more friends in a compact neighborhood emerged in this research as another influencing factor, along with a belief in being able to take public transit and being able to own fewer cars.
- Being able to “exercise by walking and biking” was rated as by respondents as the most important outcome of moving to a compact neighborhood.
- Individuals who believed that moving to a compact neighborhood would expose them to more street noise or less living space had a more negative attitude toward the move.
- Being able to find an affordable home in a compact neighborhood was a key concern that affected self-confidence.
In Phase 2 of the research, respondents’ thoughts and opinions about using a set of transportation options that could allow a reduction in the number of private automobile trips and increase the number of trips by walking and public transportation were investigated. At the start of the questionnaire, respondents were asked to rate a number of statements that expressed opinions about walking and taking transit. Following a set of messages and presentation of alternative transportation options, respondents were asked to rate a similar set of statements. The objective was to determine if exposure to messages and alternative transportation options would change respondents’ attitudes and intentions regarding walking and using transit.
The transportation options were presented to the survey respondents as follows:
We want to know your thoughts and opinions about using a set of transportation options that could allow you to reduce the number of trips you take by private automobile and increase the number of trips you take by walking and using public transportation. Assume that you have all of the following alternative transportation options available to you:
- There is fast transit service (rail or express bus) to the downtown. This service is available every 15 minutes or better, and a station is located less than a mile away.
- There are good connections by transit to the rest of the region (other than the downtown). This service may involve a transfer from one transit vehicle to another. Service is available every 15 minutes or better throughout the day.
- There is a shuttle bus that connects your street with the local community center and other activities within your neighborhood. Service is available every 15 minutes throughout the day.
- A community door-to-door service that you can take at about half the price of taxi service, that you share with others traveling at the same time. This service can be obtained by calling a special number and is immediately available.
- Cars are available on your block or near your workplace to be rented by the hour (car sharing) when you need to make a trip that is difficult to make on transit. Cars should be reserved a day in advance, but also may be available immediately.
- You have a “smart card,” which you can use to purchase service on any of the buses, shuttles, trains, or taxis. Just wave the card near the fare reader or meter, and your card will be debited the fare.
- You have a new kind of cell phone which will tell you exactly when the bus or train will arrive, show you where you are, and provide instructions on getting to your destination by public transportation. It would also have a “911” button that would instantly send your location to police or emergency services. This cell phone can serve as your normal cell phone, or your own phone can be programmed to have this capability.
The data from the Phase 2 research confirmed that there was a significant association between an individual’s intent to walk more and take more public transportation and his or her attitude. There was also an association between an individual’s intent and his or her subjective norm and self-confidence, but attitude was most influential.
Respondents’ beliefs about transit and walking showed why attitude is difficult to change. Respondents thought that walking more and using more public transportation would take more time and make them dependent on others. They rated these outcomes as undesirable.
The most positive impact on attitude came from the belief that “I would rely on alternative transportation and walking to get me to my destination in a timely way.” Also contributing to a positive attitude were the ideas that “I would improve my health and reduce pollution” and “I’d save money.” On the other hand, the belief that “I would be dependent on someone else” contributed negatively to attitude.
With the new services available, respondents significantly increased their rating of “I would rely on alternative transportation and walking to get me to my destination in a timely way.” However, they decreased their rating of “I would improve my health and reduce pollution.” Overall, their attitude towards taking transit and walking did not change. However, respondents significantly increased their belief that their families would approve of their taking transit and walking with the new services available, and, as would be predicted by the TPB, they increased their rating for the subjective norm.
The most significant relationship with self-confidence was the respondents’ concerns about being stranded. The more respondents agreed with the statement, “With the new services available, I would have less concern about being lost or stranded by missing the bus or train,” the higher their self-confidence. Additional analyses found that concerns about crime and being stranded were also highly correlated with the respondents’ normative beliefs about the approval of their family and others.
In summary, the overall message of these findings seems to be that to increase transit use and walking will require the following be accomplished:
- The perceived reliability of the system must be improved.
- The positive health and environmental effects of walking more and taking public transportation more must be more convincing.
- Customers must be convinced that they will not be left stranded.
- Families must approve of increased transit use and walking.
Overall, the TPB proved useful for understanding the motivations of the respondents. A major contribution of the theory was to show the importance of the opinions of others and of respondents’ self-confidence in the decision to walk and use transit.
The Relationship of Values, Urban Form, and Auto Ownership on Choice of Mode
The two market segments with more positive views on a move to a compact neighborhood made quite different modal choices. The TPB provides a structure for further investigation of how characteristics of respondents are associated with mode choice.
The literature review for this research revealed a debate about the relative influence of values and urban form on travel behavior. This research provides additional evidence for the debate and suggests that another factor—automobile availability and orientation—may play a larger role than either values or urban design.
To structure an investigation into the influence of values on mode choice, a simple method was used to partition all of the 865 respondents into two groups. A compound rating was developed by summing responses to a set of 15 questions on urban and environmental values. The questions included respondents’ ratings of (a) the importance of community characteristics hypothesized to be characteristics of compact neighborhoods and (b) other values related to mode choice and the environment.
First, the respondents were split into two values groups (high urban/environmental values and low urban/environmental values) using the mean of the compound rating as the dividing value. Second, to examine the influence of urban form, the respondents were broken into two groups: (a) those living in a compact neighborhood (CN) and (b) those not living in a CN. Finally, a third grouping was created by breaking respondents into (a) those respondents whose households have less than one car per adult and (b) those having one or more cars per adult. Urban form and automobile ownership levels affect the respondents’ self-confidence for selecting travel modes.
Table S-1 shows how selected travel characteristics vary by the different groups. For the two urban/environmental values groups, there is a significant difference in the percentage choosing transit and walking. Similarly, there are significant differences in this choice for the neighborhood-type groups and the auto-availability groups.
Statistical analyses of all of the variables together provided evidence that living in a compact neighborhood and having high urban/environmental values were independently and significantly associated with the choice of green modes (either walking or taking transit, or both). However, auto availability levels had greater association with green-mode choice than either living in a compact neighborhood or having high urban/environmental values.
Research Limitations and the Need for Additional Research
When considering the practical or policy implications from this research, it is important to keep in mind some inherent limitations of the research design. The use of an Internet panel brings some bias to the sample, as respondents are those with access to the Internet who are willing to respond to such surveys. While the sample did include respondents from around the country, it was limited to larger metropolitan areas with good transit. Age-groups of interest were oversampled, and respondents were limited to those who had recently moved or were contemplating moving. Indeed, this research was not intended to give results that could be projected quantitatively to a larger population. Its purpose was to increase understanding of the motivations of certain individuals who are of major interest to policymakers trying to promote smart growth and environmentally friendly modes. Future research will be needed to determine the overall incidence rate of market segments described in this study.
Another limitation relates to the specification of the models of relationships tested in the study. Using the TPB, prior research, and findings from focus group discussions as a guide, this study identified a set of independent variables that are used to explain differences or variations in attitude, subjective norm, and self-confidence, as well as intent. Although the regressions show significant results, as is often the case with individual attitudinal data sets, they typically explain relatively small percentages of the total variation in the attitude, subjective norm, and self-confidence. This means that it is possible that other important factors have been left out of these models. Hence, the practical implications that can be derived are somewhat limited or tentative. The study acknowledges the need for additional research to help further our understanding of these effects.
One of the important products from this research are the data sets that are available to researchers to explore and draw additional conclusions. These data sets will be available either on CD or on the TRB website. There are two SPSS data sets, each corresponding with the two phases of the study. In addition, there are two Excel files that hold the results of trade-off exercises. In Phase 1 of the study, there was an exercise where respondents chose their favorite residential location based on a set of features for that location. In Phase 2 of the study, there was an exercise where respondents ranked the alternative transportation services. While an extensive amount of analysis was done for this project, there is still much left to discover.
This research used the model of TPB to structure research into complex issues such as choice of residence and mode choice. Examination of the three components of the model— attitude, subjective norm, and self-confidence—provided insights into motivations that point to reinforcing policies that can be pursued by policymakers and practitioners.
From this research, the most potential for increasing transit usage appeared to come through improving subjective norm and self-confidence. Both of these components were correlated with respondents’ concerns about being left stranded by transit. The key to improving attitude was to improve transit reliability and convince respondents that transit use would reduce pollution and increase health.
The characteristic of a compact neighborhood that was most connected with a positive attitude was to be within walking distance of shops, restaurants, and other interesting destinations. The limitation that was key to self-confidence about moving to a compact neighborhood was the concern about finding an affordable home.
Market segmentation based on a set of statements correlated with intent to change modes and intent to move to a compact neighborhood also provided helpful insights. Two positive market segments were found in each case: a transit-oriented segment and an environmentally oriented segment. The transit-oriented segments already choose a compact neighborhood at a high rate and use transit at a high rate. However, the transit-oriented segments cannot be taken for granted: they want frequent transit to downtown and other destinations, and they are not necessarily loyal to living in a compact neighborhood. The environmentally oriented segments currently have a low rate of transit use and are very suburban in their current choice of neighborhood. However, they have potential and interest in increasing their use of transit and moving to a compact neighborhood. They believed that with new transit services available, it would be easier to use transit and walk more, and they believed that their family and others would approve. They also felt that with the new services, there would be less danger of being stranded.
The data collected for this research will be available to other researchers to explore. Although the sample was not representative of the national population, it is representative of the most positive markets for transit in large metropolitan areas. The research team for this project looks forward to learning of additional insights that others may discover in this data set.