Sharing mobility data without compromising privacy

In recent years, rows of electric scooters and bikes lining sidewalks have become a common sight in cities around the United States.

The size of the e-scooter market alone is expected to surpass $40 billion by 2025, and Americans have taken more than 342 million trips on shared bikes and e-scooters since 2010.

Micromobility services generate a massive amount of mobility data, including potentially sensitive precise location data about users. Data from mobility services can provide valuable and timely insights to guide transportation and infrastructure policy, but the sharing of sensitive mobility data -- between companies or between and with government agencies -- can only be justified if issues of privacy and public trust are first addressed.

Innovative mobility options are providing cities with opportunities to solve the last-mile transportation problem, and the data from these services has a range of productive uses.

It can help city planners design transportation improvements, such as protected bike lanes, to keep users safe. Access to mobility data gives community advocates and government officials the ability to know in nearly real time how many mobility devices are in a certain area so cities can enforce limits to ensure neighborhoods are not overcrowded or underserved. This data can also streamline communications between companies and city governments, making it easier for mobility services to quickly adapt to events and emergencies in cities.

However, there are valid privacy concerns over the granularity and quantity of data that digitally enabled mobility services are able to collect and request to share with governments.

For example, a recent lawsuit filed against the Los Angeles Department of Transportation and the City of Los Angeles alleges that the city’s collection of e-scooter trip data through the Mobility Data Specification violates the Fourth Amendment to the U.S. Constitution and the California Electronic Communications Privacy Act. A lower court dismissed the lawsuit and the Electronic Frontier Foundation and the ACLU of Northern and Southern California recently asked a federal appeals court to revive it.

Additionally, a bill recently introduced in the California Legislature would require specific conditions to be met before mobility data is shared with public agencies or contractors. Under this bill, data could only be shared to assist transportation planning or protect the safety of users. The bill also requires that any trip data must be more than 24 hours old before being shared.

Near-real-time location data is often required to fulfill valid safety and regulatory enforcement purposes, but this data is very sensitive because it could reveal intimate aspects of an individual’s life. Patterns in location data could indicate personal habits, interpersonal relationships or religious practices.

While it is possible in some cases to “de-identify” location data tied to a specific individual or device, it is incredibly difficult to truly make any data set of precise location history truly anonymous. Even highly aggregated location data about patterns of large groups of people can unintentionally reveal sensitive information.

In 2017, a “global heat map” of user movement in the Strava fitness app inadvertently revealed the location of deployed military personnel in classified locations. Location data, even when de-identified or aggregated, should be subject to checks and controls to ensure the data remains protected and private.

Local governments and mobility companies are taking these issues of user privacy seriously. Over the past few months, the Future of Privacy Forum has worked with SAE’s Mobility Data Collaborative and public and private stakeholders to create a transportation-tailored privacy assessment tool that focuses on considerations for organizations that want to share mobility data in a privacy-sensitive manner.

The Mobility Data Sharing Assessment (MDSA) provides organizations in both the public and private sectors with operational guidance to conduct thoughtful, in-depth legal and privacy reviews of their data-sharing processes. Organizations that use this tool for sharing mobility data will be able to embed privacy and equity considerations into the design of mobility data-sharing agreements.

The goal of the MDSA is to enable responsible data sharing that protects individual privacy, respects community interests and equities, and encourages transparency to the public. By equipping organizations with an open-source, interoperable, customizable and voluntary framework that includes guidance, the barriers to sharing mobility data will be reduced.

This is the first version of the MDSA tool; it focuses specifically on ground-based mobility devices and location data. Some mobility vehicles like e-scooters now come equipped with on-board cameras, so in the future, the MDSA may be appended to add guidance about images and video collected by mobility devices.

The MDSA tool is open source and customizable, so organizations sharing this type of mobility data can edit it to consider the risks and benefits of sharing sensor or camera data that includes images.

Micromobility services can play a key role in improving access to jobs, food and health care. However, there are multiple factors for companies and government agencies to consider before sharing mobility data with other organizations, including the precision, immediacy and type of data shared. Organizations must assess these factors in a thoughtful, structured manner that considers any potential sources of bias.

That’s the key to using mobility data to maximize the benefits of services in the short term and build their infrastructure in the long term, allowing people to move about cities safer and faster.