Web-Based Survey
The web-based survey asked respondents to report details about two recent trips that they took on the Uxbridge Corridor. More than 9,000 people (an 18% response rate) responded to the survey, and they provided complete, valid information for about 4,505 trips. In addition to information about their recent trips, they responded to statements about their attitudes towards crowding, waiting time, in-vehicle time, walking time, and their levels of risk aversion, and level of trust in countdown information. Finally, the individuals responded to basic demographic questions about their age, income, gender, and whether or not they have any disabilities that affect their experience as a bus passenger.
from a large sample of individuals at very low cost. A few issues with the representativeness of the responses were identified. Elderly and disabled passengers were under-represented due to the fact that they are less likely to provide TfL with an email address. This bias could be overcome with targeted paper surveys mailed to these individuals. Respondents were more likely to report trips they took on Route 607 and less likely to report trips they took on Route 427. Regardless of route, they were more likely to report longer trips. This could be addressed by providing users with a summary of their recent Oyster card activity on the corridor so that they can remember which route they took and do not forget or disregard shorter trips. Some users appear to have been confused by certain questions, and there was some amount of incompleteness likely due to a combination of survey fatigue and passengers failing to remember certain details. However, the benefit of an online survey is that due to the large volumes of data that can be collected, even with incomplete or questionable responses discarded, large sample sizes remain.
Analysis of the sample data revealed that many factors influence passenger behavior on the Uxbridge Corridor. As the analysis of AFC and AVL data inferred, trip length was found to be highly correlated with a preference for the limited stop service route, Route 607. Respondents’ attitudes towards crowding, walking and waiting time and their levels of risk aversion were also strong predictors of their route choice strategies. Crowding averse people tend to opt for less-crowded local buses when boarding at stops where Route 607 buses are especially crowded. Respondents who reported a strong aversion to waiting time were less likely to wait for Route 607 buses. Those who expressed a dislike of walking were more likely to board at a local stop. Passengers who are more risk averse are more likely to take the first bus, rather than waiting for a specific bus route.
Respondents also showed a clear connection between their use of countdown information and their decision to wait for a particular bus route. Those who used countdown information were less likely to have a first bus strategy. Crowding, income, and trip purpose are also likely to be important influences of route choice behavior. Due to correlations between these factors and other influences more analysis is needed to clearly see the effect of these factors in isolation.The analysis of these influential factors and their correlations with the route choice strategies reported forms a foundation that can be used to inform the structure of a model that estimates route choice strategy based on a set of explanatory factors and conditions. Such a model can be used subsequently for prediction of response to network and service changes, and evaluation of trade-offs between factors such as walking, waiting, and in-vehicle time.
8.3
Implications of the Strategy Analysis
Given the prevalence of a first bus strategy on the Beulah Corridor, and the high volume of overall passengers, including many with first bus strategies on the Uxbridge Corridor, there is a potential benefit of planning vehicle schedules and controlling operation at a corridor level. Currently, because each route is scheduled and operated in isolation, pas- sengers who are able to board multiple bus routes experience uneven combined headways. If schedules can be set at the corridor level, equalizing headways between multiple routes, waiting time can be reduced for those individuals who have first bus strategies. On the Uxbridge Corridor, maintaining even headways between limited stop service and local ser-
vice is likely impossible, but the headways of the two local routes could be equalized, or headway coordination at specific stops can be attempted.
The existence of stops within the corridor that are not shared between the corridor routes, but rather are located a block or more apart, prevent individuals who board at these stops and alight at other stops in the corridor from using a first bus strategy and benefiting from a shorter waiting time. These shared boardings should be taken into consideration when deciding where to locate stops for specific routes.
Load imbalances between the routes on the Uxbridge Corridor suggest that the current allocation of vehicles between the local and limited stop routes is not optimal. This corridor stands to benefit from a reduction in local service, particularly in the middle portion of the corridor and an increase in limited stop service. Planners should be aware of the expected interaction between service frequency, crowding, and passenger route choice strategies when changing service frequencies on the corridor.
When considering the implementation of limited stop service, more generally, the findings of the thesis suggest that a strong preference for limited stop service is likely to be found on corridors with long trip lengths and a high volume of work and school trips. Providing countdown information on a corridor along with the introduction of limited stop service will likely increase the demand for the limited stop route.