Potential data collection methods

Several methodologies, as presented in this subsection, were investigated in terms of their advantages and drawbacks, and their technical or resource feasibility. Table 5.1 indicates these possible methods, describes them and balances the pros and cons for each.

Table 5.1 Potential data collection methods: description, pros and cons Potential data

collection method

Description of the method

Pros Cons

Simulation with stated preference

A software program could have been developed to simulate a virtual

environment with a stated preference choice survey of travel information and travel choices.

Chapter 5. Data collection protocol Potential data

collection method

Description of the method

Pros Cons

survey The advantage would be that the sensitivity of certain characteristics could be better modelled. Multiple scenarios could be created for the search, acquisition and processing of information; for example, time spent and amount of information consulted could be closely monitored.

Simulations and stated-preference have usually been used to validate models representing the impact of travel information (Pathan et al. 2011; Chorus et al. 2013).

These rarely, however, emulate the variety of information sources available in reality and the associated effort required in real life in order to search and acquire information from these different sources. Simulating a virtual environment also requires a

considerable amount of time and programming-specific skills, which rendered this option infeasible in the context of this PhD.

Module added to existing travel diary

Due to its own extent, Transport for London (TfL) uses a tailored data collection method, the London Travel Demand Survey (LTDS). The option of adding a “travel information use” module to the TfL’s existing travel diary was considered. The module would be added to an

already rich dataset with a valid data collection method for demographics and travel patterns, and a set of respondents that would fit the sampling frame.

Having this module was investigated with TfL but could not be pursued based on their response. In their view and in current conditions, the benefits in terms of research did not justify the cost for this added module. If they had accepted, the amount of time spent in agreement and administration would have been considerable.

Data collection from diary/survey app for mobile phone

An application for mobile phone devices could be created as a sort of diary for information and travel. Web usage for information and transport-related apps, as well as GPS tracker data could be reported precisely.

Using this data collection app would bring a lot of accuracy in terms of real-life information use: frequency, time duration, exact app and webpage consulted (while it would be recalled in an RP). Also, the GPS tracker would bring greater accuracy to the travel pattern variables.

This application faced many

challenges: working under limited time constraints, finding appropriate app programming resources, creating and distributing the app to respondents, identifying a representative sample of a population. This was not a feasible option given the time and technical resources available.

Revealed preference survey

A revealed preference survey could be developed using an online platform. A dissemination method and survey design should be planned to achieve the target sample frame.

Chapter 5. Data collection protocol Potential data

collection method

Description of the method

Pros Cons

The main advantage of an RP-survey is the flexibility to tailor easily the survey in terms of questions, time, and resources Zmud and Lee-Gosselin (2013). This allows a complete control of the type of questions and the feasibility within the PhD timeline. The questions could be easily customised towards the research objectives, and practically could be changed from the pilot to the final survey. The platform allowed the creation of an interactive environment, where responses affect the following questions. As mentioned in the literature review in Chapter 2, very few studies use revealed preference data and this would therefore be an innovative approach.

The challenge was to collect revealed preference data and obtain as much detail as possible using a stated preference one. The amount of use or “consumption” of travel information sources captured by travellers is difficult to collect and quantify but much attention has been paid to this aspect when creating the questionnaire. In addition, RP questions rely not only on respondents’ perceptions but also on their recollections of their actions and observations, which will introduce some bias into the results.

After consideration of all possible methods, the revealed preference survey was selected because of the customisation possibilities and the feasibility within the scope of the PhD work. Since it was based on recalling observations and actions, the survey was retrospective rather than prospective. The first part looked at general TI acquisition while the second collected data about a specific example of TI acquisition that occurred recently. Because of the variety of the questions, the RP survey could also be defined as a cross-sectional study and is used to scrutinise information acquisition and travel behaviour, alongside demographics and attitudinal questions.