1. This slide brought to you by What to Do With Thousands of GPS Tracks John Krumm, PhD Microsoft Research Redmond, WA

2. This slide brought to you by GPS Data Microsoft Multiperson Location Survey (MSMLS) 55 GPS receivers 227 subjects 1.77 million points 95,000 miles 153,000 kilometers 12,507 trips Home addresses & demographic data Greater Seattle Seattle DowntownClose-up Garmin Geko 201 $115 10,000 point memory median recording interval 6 seconds 63 meters

3. This slide brought to you by GPS Projects Personalized Routes Predestination Location Privacy

4. This slide brought to you by Personalized Routes Percentage of trips in our data for which the driver’s actual route matched the… Shortest route: 27% Fastest route: 31% MapPoint route: 39% Neither shortest nor fastest: 60% Empirically fastest Shortest distance MapPoint plan Driver’s route One Driver A to B: Julia Letchner, John Krumm, and Eric Horvitz, "Trip Router with Individualized Preferences (TRIP): Incorporating Personalization into Route Planning", Eighteenth Conference on Innovative Applications of Artificial Intelligence (IAAI-06), July 2006.

5. This slide brought to you by Preferable Routes One trip from GPS data Deflate cost of previously driven roads Tested on ~2500 trips 47% of computed routes matched actual Only 11% of trips duplicated in data (Note: people who liked this slide also liked the next slide)

6. This slide brought to you by Dynamic Map Matching Goal: Infer actual route from noisy location data John Krumm, Julie Letchner, and Eric Horvitz, "Map Matching with Travel Time Constraints", Society of Automotive Engineers (SAE) 2007 World Congress, April 2007, Paper 2007-01-1102. Results on traditional problem cases

7. This slide brought to you by Predestination Where do you want to go today? We already know. Traffic Warning Destination Safeco Field (54% chance): 15-minute delay at I-405 & I- 90. Suggest I-5 instead. Destination Seattle Center (31% chance): Broad St. closed. Suggest Denny Way instead. Going to the airport? Park with us for $8/day! Regular nav systemUpcoming trafficRelevant ads Optimize hybrid charge/discharge John Krumm and Eric Horvitz, "Predestination: Inferring Destinations from Partial Trajectories", Eighth International Conference on Ubiquitous Computing (UbiComp 2006), September 2006.

8. This slide brought to you by Predestination Previous destinations Preferred ground cover Efficient driving Anticipated trip times USGS Ground Cover: swamps unpopular as destination (1)(2)(3) Median error = 2 kilometers at halfway point of trip John Krumm and Eric Horvitz, "Driver Destination Models", Eleventh International Conference on User Modeling (UM 2007), June 25-27, 2007, Corfu, Greece.

9. This slide brought to you by Location Privacy Congestion PricingLocation Based ServicesPay As You Drive (PAYD) Insurance Collaborative Traffic Probes (DASH)Research (London OpenStreetMap) John Krumm, "Inference Attacks on Location Tracks", Fifth International Conference on Pervasive Computing (Pervasive 2007), May 13-16, 2007, Toronto, Ontario, Canada. Why reveal your location to a 3 rd party?

10. This slide brought to you by Attack Outline Anonymized GPS tracks Infer home location Reverse white pages for identity Median error = 61 meters Correct name on 5%

11. This slide brought to you by Computational Countermeasures Uncorrupted DataSpatial Cloaking Gaussian Noise, σ = 50 m Discretize, Δ = 50 m Mention this talk at any participating* Pizza Hut and receive free breadsticks! * There are actually no participating Pizza Huts.

12. This slide brought to you by How Much Corruption? Gaussian Noise, σ = 50 m Discretize, Δ = 50 m

13. This slide brought to you by Done GPS DataPersonalized RoutesMap Matching Driver ModelsPredestinationLocation Privacy HowsMyTalk.com How’s my talk? 1-800-555-TALK