Applying GPS Data to Understand Travel Behavior, Volume I: Background, Methods, and Tests (2014)

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97 Travel Survey Practitioners and Travel Survey Researchers Please answer the following questions within the context of any travel behavior surveys in which you, your agency, or your organization may have been involved (including household travel surveys, transit studies, visitor surveys, and establishment surveys). 1. Please describe the use of technologies in the collection of travel behavior information at your organization or firm. Specifically, please include details of how GPS data are collected, processed, and leveraged. For the purpose of this project, it would be helpful to understand what GPS technologies or methods were used in the past as well as are used in the present. 2. What plans do you or your organization have for near- term or longer-term collection or use of GPS data (or other location-based data) for better understanding travel behav- ior? Please provide as much detail as possible regarding future technology needs or plans. 3. If you have used GPS devices and/or smart phones with GPS in your travel behavior studies, please discuss how the use of these technologies may have affected recruit- ment rates, retrieval rates, and sample representativeness. 4. Please explain how you or your firm processes GPS data or other location-based data to answer your research questions or the research questions of your clients. 5. Please describe the GPS-based or other location-based travel behavior details that are included in your data sets or in deliverables to your clients. 6. Please explain how confidentiality is maintained for sur- vey participants who provide GPS data in your studies. Describe any issues or concerns regarding participant privacy that you have encountered in a GPS-specific, cell phone, or other location-based technology study. 7. Overall, how does the coverage and accuracy of GPS data and/or cell phone data compare with previously used methods? (Please elaborate on previous methods as well.) If you are collecting or using mobile phone data, please elaborate on the source of the location information (i.e., from the GPS chip, from cell phone tower locations or handoffs, or from participant self-report) as well as the coverage and accuracy levels obtained. 8. Given your experience to date, what do you consider to be the advantages of using GPS or other location-based technologies for the collection of travel behavior? 9. Given your experience with using GPS or other location- based technologies to measure travel behavior, what do you consider to be the limitations or concerns for these technologies? (Please be specific.) 10. If applicable, please provide cost information that could be used by agencies that are considering adding GPS or other location-based technologies to their travel behavior surveys—either as an addition or instead of traditional methods. Types of costs could include cost per house- hold, per person, or per travel day. Please explain as much as possible. Transportation Planners and Travel Demand Modelers 1. Please describe the current role of GPS data within your organization or within your daily work responsibilities (for example, is GPS data leveraged to determine trans- portation network speeds, for congestion management, or for travel behavior analysis); please provide details. 2. Please describe the specific role of GPS data in your model development process (for example, to calculate trip rate correction factors or to evaluate baseline networks). 3. Please describe any secondary applications of GPS data in which you or your organization acquired GPS data for one purpose but then used for another/additional purpose (such as for congestion management planning, bike/pedestrian planning, or transit planning). A P P E N D I X B Industry Expert Questionnaires

98 4. Please describe any future plans you or your organization/ firm have for using GPS data to support travel demand modeling data needs. 5. Please describe others sources of measured origin– destination data that you have used or plan to use to support model development (such as data provided by INRIX, TomTom, NAVTEQ, AirSage, or other similar sources). 6. Have you purchased any advanced travel behavior data (GPS, Bluetooth, cell-phone–based data, or other origin– destination data) in the last 12 months? If so, can you briefly describe what you purchased, the intended pur- pose, and any challenges you faced with its integration? 7. Please describe your plans for using short-term model- ing tools for evaluating transportation improvements (i.e., dynamic transportation models) and identify what you see as the key data needs for short-term forecasts. 8. If you are involved in long-term transportation forecasts, what do you believe to be the key data needs in this mod- eling area? 9. If you are using or building an activity-based model, what travel behavior data quality issues are most critical from your perspective? 10. What benefits do you believe can be gained by leveraging GPS data to better understand travel behavior? 11. What disadvantages or limitations do you believe exist with using GPS data for modeling travel behavior? 12. How accurate do you believe GPS data should be for modeling travel behavior? What resolution or frequency of GPS locations do you believe is needed? 13. Do you have a plan/idea for using advanced travel behavior data (such as GPS or Bluetooth/sensor data) for some pur- pose but lack the technical capabilities for its application? 14. Describe your level of knowledge regarding advanced travel behavior data collection and provide the primary sources of your knowledge and training (such as formal classes, conference presentations, research papers, meet- ings with vendors, or personal exploration). If you need training or reference materials, please explain what train- ing methods or materials you prefer. 15. Is there anything else you would like to say about the use of GPS data for understanding travel behavior? Traffic Data Providers 1. Describe the primary and secondary markets for your data products (i.e., real-time traffic, transportation plan- ning, etc.) 2. List and describe the different data-generating technolo- gies that are used to build your company’s data products (for example, in-dash navigation devices, personal navi- gation devices, non-GPS cell phones, GPS cell phones, truck GPS/AVL). Is one technology primary; if yes, please identify. 3. If you are using personal mobile devices (such as cell phones or smart phones) as a data source, please describe the penetration rate of this data source. 4. Describe your company’s plans for future vehicle or per- sonal technology and data product development. 5. What is your current geographic coverage? Do you have plans to expand? If so, please elaborate on the planned geography as well as implementation timeline. 6. Describe any of your data products’ limitations that are relevant to road functional classification or other trans- portation system characteristics. Are expected error ranges provided by road segment or TMC [Traffic Message Channel] location code? 7. Describe how your products are packaged to specifi- cally serve the needs of transportation planners for travel demand forecast modeling or for congestion manage- ment programs. 8. For each of your specific data products (copy and repeat this question and categories as needed), please describe the following: – Data product name and description – Raw data frequency and accuracy – Data cleaning process – Level of aggregation or disaggregation – Cost structure 9. Describe any potential demographic bias that exists in your data sources. 10. Describe any data usage clauses of agreements that come with new vehicle/device purchases that enable or autho- rize your firm to use personal mobility data. 11. Describe how data source privacy and location/time of day details are protected.