Cell Phone Traffic Data Cell Phone Traffic Data Technology Demonstration in Technology Demonstration in

MinnesotaMinnesota

ITS America 2007 Annual ITS America 2007 Annual Meeting & ExpositionMeeting & Exposition

Bernie Arseneau, Mn/DOTRashmi Brewer, Mn/DOT

Dr. Henry Liu, University of MinnesotaAdam Danczyk, University of Minnesota

June 2007

Advantage of Cell Phone Advantage of Cell Phone Probe-based Tracking Probe-based Tracking

• Cell Phone TrackingCell Phone Tracking– Over 215 Million Cell Phones NationwideOver 215 Million Cell Phones Nationwide– Infrastructure already presentInfrastructure already present– Offer point-to-point travel times/speeds Offer point-to-point travel times/speeds

compared with the loop detector’s compared with the loop detector’s “Estimation”“Estimation”

– Does not require installation of new Does not require installation of new detectorsdetectors

How the Cell Phone System How the Cell Phone System WorksWorks

Road Segments and Cell Boundaries

AirSage CoverageAirSage Coverage

Project PartnersProject Partners

• Mn/DOTMn/DOT– FundingFunding– Evaluation supportEvaluation support

• AirSage, Inc.AirSage, Inc.– Provides cell phone traffic data systemProvides cell phone traffic data system– Contractual agreement with Sprint, providing the Contractual agreement with Sprint, providing the

cell phone networkcell phone network

• University of Minnesota, Center For University of Minnesota, Center For Transportation StudiesTransportation Studies– Evaluation and data collectionEvaluation and data collection– Overall evaluation reportOverall evaluation report

• Hennepin CountyHennepin County– Business PlanBusiness Plan

Evaluation ApproachEvaluation Approach

• Freeway Section (I-394)Freeway Section (I-394)– Compare with loop detector travel time dataCompare with loop detector travel time data

• High Speed Signalized Roadway (T.H. 55)High Speed Signalized Roadway (T.H. 55)– Compare with floating car dataCompare with floating car data

• Urban Signalized Roadway (CSAH 81)Urban Signalized Roadway (CSAH 81)– Compare with manual license plate matching Compare with manual license plate matching

datadata

**

Freeway Section (I-394) Freeway Section (I-394) DescriptionDescription

• Loop DetectorsLoop Detectors– ½ mile spacing½ mile spacing

• 30-Second Data30-Second Data

• Existing Mn/DOT Existing Mn/DOT Travel Time SystemTravel Time System

High Speed Signalized High Speed Signalized Roadway (T.H. 55) DescriptionRoadway (T.H. 55) Description

• Full Actuated Full Actuated Coordinated Traffic Coordinated Traffic Signal System Signal System

• Floating Car Will Floating Car Will Assess Travel TimesAssess Travel Times

**

Urban Signalized Roadway Urban Signalized Roadway (CSAH 81) Description(CSAH 81) Description

• Semi-Actuated Coordinated Semi-Actuated Coordinated Traffic Signal SystemTraffic Signal System

• License Plate SamplingLicense Plate Sampling

• Use Digital Voice Use Digital Voice Recorders to collect last Recorders to collect last 4 4 license plate digitslicense plate digits

Plate Plate

LetteLetterr

NumbeNumber r

11

NumbNumberer

22

NumbNumberer

33

Upstream Upstream

Entry Entry TimeTime

DownstreaDownstream m

Entry TimeEntry Time

TraveTravel l

TimeTime

FF 55 44 22 4:05:24:05:200

4:08:584:08:58 3:33:388

Data CollectionData Collection

• AirSage, Inc.AirSage, Inc.

• Mn/DOTMn/DOT

• U of MU of M

Data Sample for Freeway Data Sample for Freeway Section Section

(I-394) AM Peak(I-394) AM PeakI-394 AM Peak Hour (I-494 to U.S. 169)

0

50

100

150

200

250

300

350

400

450

5:30:00 AM 6:30:00 AM 7:30:00 AM 8:30:00 AM 9:30:00 AM

Time of Day

Tra

vel T

ime

(sec

)

Observed

AirSage

Data Sample for Freeway Data Sample for Freeway Section (I-394) PM PeakSection (I-394) PM Peak

I-394 PM Peak Hour (I-494 to U.S. 169)

0

50

100

150

200

250

300

350

400

450

3:00:00 PM 4:00:00 PM 5:00:00 PM 6:00:00 PM 7:00:00 PM

Time of Day

Tra

vel

Tim

e (s

ec)

Observed

AirSage

Data Sample for High Speed Data Sample for High Speed Signalized Roadway (T.H. 55)Signalized Roadway (T.H. 55)

T.H. 55 12-Hr Data (Arrowhead to Peony)

0

50

100

150

200

250

300

350

400

450

6:00 7:30 9:00 10:30 12:00 13:30 15:00 16:30 18:00

Time

Tra

vel T

ime

(sec

)

Observed

AirSage

Data Sample for High Speed Data Sample for High Speed Signalized Roadway (T.H. 55)Signalized Roadway (T.H. 55)

T.H. 55 12-Hr Data (I-494 to U.S. 169)

0

100

200

300

400

500

600

700

800

900

1000

1100

6:00 7:30 9:00 10:30 12:00 13:30 15:00 16:30 18:00

Time

Tra

vel T

ime (

sec)

Observed

AirSage

Data Sample for Urban Data Sample for Urban Signalized Roadway (CSAH 81) Signalized Roadway (CSAH 81)

AM PeakAM PeakCSAH 81 AM Peak (CSAH 30 to U.S. 169)

0

100

200

300

400

500

600

7:50 8:00 8:10 8:20 8:30 8:40 8:50 9:00

Time

Tra

vel T

ime

(sec

)

Observed

AirSage

Data Sample for Urban Data Sample for Urban Signalized Roadway (CSAH 81) Signalized Roadway (CSAH 81)

PM PeakPM PeakCSAH 81 PM Peak (CSAH 30 to U.S. 169)

0

100

200

300

400

500

600

700

800

16:15 16:25 16:35 16:45 16:55 17:05 17:15 17:25 17:35 17:45

Time

Trav

el T

ime

(sec

)

Observed

AirSage

Statistical AnalysisStatistical Analysis

• Aggregated Scale Aggregated Scale – Paired T-Test Evaluation Paired T-Test Evaluation

• Based on Time of Day (AM Peak, Mid-day, PM Peak, Based on Time of Day (AM Peak, Mid-day, PM Peak, Evening, Weekend Day, Weekend Evening, etc.)Evening, Weekend Day, Weekend Evening, etc.)

• Disaggregated Scale Disaggregated Scale – Percentage of time that AirSage’s value falls Percentage of time that AirSage’s value falls

within 90% confidence intervalwithin 90% confidence interval– Exception for T.H. 55, as it does not have a Exception for T.H. 55, as it does not have a

continuous data source continuous data source

• Hypothesis TestingHypothesis Testing

Next StepsNext Steps

• Continued Data CollectionContinued Data Collection

• Statistical AnalysisStatistical Analysis

• Final Report – Fall 2007Final Report – Fall 2007

Future/OpportunitiesFuture/Opportunities

• It’s success depends on statistical It’s success depends on statistical confidence when compared with ground confidence when compared with ground truth conditionstruth conditions

• If results are positive, then cell phone If results are positive, then cell phone tracking will likely offer a promising future tracking will likely offer a promising future for travel time estimationfor travel time estimation

Thank you!Thank you!Questions?Questions?