Transportation agencies need travel behavior data to plan changes to their networks, systems, and policies. A new smartphone application developed by a U of M research team makes it easier and less costly to collect this important information and provides richer, more accurate data than traditional methods.
The Daynamica open-source app provides an efficient approach for collecting and processing data for driving, walking, biking or taking transit. It combines smartphone GPS sensing with statistical and machine-learning techniques to detect, identify, and summarize daily activity and travel episodes. The app then allows users to view and annotate information at their convenience.
In contrast, traditional travel survey methods—commonly, paper diaries—are often burdensome to study subjects and increasingly impractical for use. And while GPS sensing tools can collect data about travel mode, position, and route, they are unable to obtain key dimensions such as trip purpose, travel experience, and travel companionship—factors Daynamica includes.
“All of these factors are critical for understanding people’s travel choices,” says Yingling Fan, associate professor in the Humphrey School of Public Affairs and principal investigator for the work. “Daynamica gives us the best of both worlds: It captures many more dimensions of travel behavior data than either GPS sensing or travel surveys can alone.”
Daynamica places a much lower burden on users to recall and record their activities compared with traditional surveys, resulting in more accurate and detailed data. Lower user burden could also allow agencies to lengthen the time studied.
Unlike other apps, Daynamica hosts both the data obtained from sensors and the data entered by users in a single device and enables interaction between the two data sources in real time. This in turn allows for data calibration and processing refinements over time. “The algorithm learns from past mistakes,” Fan explains. “As it gets smarter, users need to make fewer corrections. After about a week of use, most data collection is automated. It learns what your location is—home, job, day care, or grocery store, for example—and remembers it.”
Daynamica is easier to distribute and manage than other technologies because it does not involve providing additional devices or instruments to respondents if they already own a smartphone. Users only need to download the Daynamica app and install it on their phone, and updates can be provided to users quickly and easily.
Although currently targeted for agency use only, plans are to form a start-up company to commercialize the app for the general public.