CLIENT PROJECT / ENGM 204 DATA ANALYTICS PROJECT LAB × GOOGLE MAPS
Google Maps: Privacy-Conscious GPS Insights. GPS traces make the map better, and four data points can identify a person.
Google Maps / Privacy-Conscious GPS Insights
- Team
- Aayush Gujrathi, Joe Gehl, Shalini Dasararaju
- Timeline
- Mar to Jun 2026
- Stack and methods
- Python, OSRM, k-anonymity, Differential privacy, GDPR
We owned the project end to end as a team.
- 7 privacy methods evaluated
- 15,000 synthetic trips/day
- 20 km² simulated Seattle network
- 97.9% precision (segment statistics)
Privacy tradeoff explorer
Interactive / try itThe problem
Google Maps relies on GPS road-traversal data for road geometry, speed limits, traffic patterns, and incident detection. The same data can reveal home and work addresses and daily routines. The tension is utility versus individual privacy.
What we did
- Defined "anonymous" for geospatial traversal data: no trip, pattern, or sequence can be tied back to a person.
- Built a Seattle road-network simulation with rush-hour peaks, speed variation, GPS noise, connection loss, and three obstruction types (traffic, construction, accidents).
- Evaluated seven privacy methods across three layers (collection, mathematical, architectural): data minimization, identifier removal, k-anonymity, differential privacy, segment statistics, leader-follower, and hallucination privacy.
- Added a detection baseline that flags segments dropping to 20% or less of their four-week historical trip count.
- Built a Python dashboard that compares methods on coverage, freshness, anomaly counts, and privacy budget with configurable k and epsilon.
- A sponsor reality check partway through reshaped the framework.
Grounding
GDPR principles framed the work: legitimate interest, data minimization, purpose limitation, and privacy by design.
Decisions worth asking about
Define anonymity before building anything.
Rejected: Jumping straight to techniques.
Without a definition there is no way to judge a method.
Simulate, and say so.
Rejected: Waiting for real data.
A realistic synthetic network let us measure every method on the same traffic, and we flagged validation as the first gap.
No single winner.
Rejected: Recommending one method.
Each method wins on a different dimension, so the right choice depends on traffic volume and event type.
Outcome and limitations
A recommended framework that matches privacy methods to event duration.
Limitations
- Results use synthetic GPS traces and need real-world validation.
- Detection thresholds were tuned on simulated data.
- Leader-follower spoofing risk is unquantified.
- Google's internal methods are not public, so there is no direct comparison.