Frequently asked questions

Q. Why not share raw data with end-users directly?

Barriers to data sharing would appear simple to solve, if not for the need to protect the privacy of the persons identified in the data and the potential for the results to increase rather than decrease inequity. To track people over space and time is the very essence of surveillance. Data about travel often contains personal information and can be used—with relatively little effort—to personally identify individuals.

As Montjoye et al. (2013) have shown, in their study of the hourly tracking of 1.5 million devices by MAC address over 15 months, only four spatio-temporal data points per day are needed to identify 95 percent of the owners of those devices. And within the spatial scale of a municipality, re-identification is further eased by pinpointing one’s home and workplace as the origins and destinations of daily trips (Whittington et al. 2015).

Q. Are there any laws against sharing individuals' location traces?

In most cases, individuals' geospatial data is not yet protected under state and federal law. However, public agencies and companies should protect data privacy to preserve the public trust. In the US, 9 out of 10 people surveyed in Pew Research (2015) say it is important that they be able to control what information is being collected about them, determine who can get it, and be able to share it with those they trust.

Regulations in the European Union are aligning with such sentiments. In sharing their data with one another and in response to public disclosure requests, transportation providers will be challenged to maintain the privacy of the persons identified in the data. To trust a platform with one’s sensitive data is to have confidence that the platform will be managed with care for the security and the privacy of persons as well as the organizations represented by the data.

Q. Is the TDC available in my area?

The operations of TDC are based in Seattle, but will serve other major metropolitan areas as its services come online.