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.

7Privacy methods, one framework

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 it

The 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

Decision 01

Define anonymity before building anything.

Rejected: Jumping straight to techniques.

Without a definition there is no way to judge a method.

Decision 02

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.

Decision 03

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.