1 natmec 2008 christopher monsere kristin tufte, robert l. bertini, and soyoung ahn intelligent...

1NATMEC 2008NATMEC 2008

Christopher Monsere Christopher Monsere Kristin Tufte, Robert L. Bertini, and Soyoung AhnKristin Tufte, Robert L. Bertini, and Soyoung AhnIntelligent Transportation Systems LaboratoryIntelligent Transportation Systems LaboratoryMaseeh College of Engineering and Computer ScienceMaseeh College of Engineering and Computer SciencePortland State UniversityPortland State University

Techniques for Establishing and Measuring Techniques for Establishing and Measuring Data Quality in an Archived Data User ServiceData Quality in an Archived Data User Service

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Data QualityData Quality

As usage expands, so does data quality expectations

Initial use of ATMS Fixed-time ramp metering, incident identification

Next Traveler information

Expanding Use Adaptive ramp metering (SWARM), Performance

measurement (travel time validation, bottleneck identification, emissions)

As usage expands, so does data quality expectations

Initial use of ATMS Fixed-time ramp metering, incident identification

Next Traveler information

Expanding Use Adaptive ramp metering (SWARM), Performance

measurement (travel time validation, bottleneck identification, emissions)

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What’s in the PORTAL Database?What’s in the PORTAL Database?

Loop Detector DataLoop Detector Data20 s count, lane occupancy, 20 s count, lane occupancy, speed from 500 detectors speed from 500 detectors

(1.2 mi spacing) (1.2 mi spacing)

Incident DataIncident Data140,000 since 1999140,000 since 1999

Weather DataWeather DataEvery day since 2004Every day since 2004

VMS DataVMS Data19 VMS since 199919 VMS since 1999

DaysDaysSince July 2004Since July 2004About 300 GBAbout 300 GB

4.2 Million Detector 4.2 Million Detector IntervalsIntervals

Bus DataBus Data1 year stop level data1 year stop level data

140,000,000 rows140,000,000 rows

001497

WIM DataWIM Data22 stations since 200522 stations since 2005

30,026,606 trucks30,026,606 trucks

Crash DataCrash DataAll state-reported crashes All state-reported crashes

since 1999 - ~580,000since 1999 - ~580,000

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Our Vision for Data Quality ImprovementOur Vision for Data Quality ImprovementOur Vision for Data Quality ImprovementOur Vision for Data Quality Improvement

ODOT - Operations

ODOT - Maintenance

PSU – Archive

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PORTAL Data Quality ObjectivesPORTAL Data Quality Objectives

Systematically identify erroneous detector data

Prioritize detectors in need of maintenance Monitor and disseminate data quality

information

Systematically identify erroneous detector data

Prioritize detectors in need of maintenance Monitor and disseminate data quality

information

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PORTAL Data Fidelity PlotPORTAL Data Fidelity PlotPORTAL Data Fidelity PlotPORTAL Data Fidelity Plot

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Detection of Malfunctioning DetectorsDetection of Malfunctioning Detectors

Count > 17 (≈ 3060 vph)* Occupancy > 95 %* Speed > 100 mph* Speed < 5 mph* Low maximum occupancy (thresholds vary

by locations) Low average occupancy during peaks

Count > 17 (≈ 3060 vph)* Occupancy > 95 %* Speed > 100 mph* Speed < 5 mph* Low maximum occupancy (thresholds vary

by locations) Low average occupancy during peaks

* Adapted from criteria proposed by TTI

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Identifying Malfunctioning DetectorsIdentifying Malfunctioning Detectors

Two primary categories of loop detector malfunction Detector or controller configuration errors Communication failures

Two primary categories of loop detector malfunction Detector or controller configuration errors Communication failures

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Configuration Errors ReportConfiguration Errors Report

Detect. Location Milepost Lane Tests Failed

1011 I-5 N Rd WB to NB 286.3 3 Low Avg Occ1244 I- SB Swift Blvd 307.35 1 Speed < 51123 I-5 N Multnomah Blvd NB 296.6 3 Occ > 95, Speed < 51204 I-5 N Denver Ave NB 306.51 2 Low Max & Avg Occ1205 I-5 N Denver Ave NB 306.51 3 Low Avg Occ1206 I-5 N Denver Ave NB HOV 306.51 1 Low Avg Occ1212 I-5 N Delta Park NB 306.51 2 Low Max & Avg Occ1695 US 26 West Skyline Rd WB 71.07 3 Occ > 951637 US 26 East 185th Ave SB 64.6 2 Occ > 951787 I-205 43 NB-NB 9.03 2 Low Avg Occ1481 I-84 West 33rd WB 2.1 2 Speed < 5

All weekdays in June 2006

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A Good Detector…A Good Detector…

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Observed Data Quality IssuesObserved Data Quality Issues

I-5 N Delta Park; Lane 2 (July 26, 2006)

I-84 W 33rd; Lane 2 (July 27, 2006)

I-5 S Swift Blvd; Lane 1 (July 27, 2006)

US 26 W Skyline; Lane 3 (July 20, 2006)

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Site VisitsSite Visits

Visited three detector stations with UW ALEDA tool for calibrating loop detectors

Stations visited: I-5 NB – Multnomah

High number of readings with occupancy > 95% I-5 NB Terwilliger

Low maximum occupancy I-5 NB OR 217/Kruse Way

Low overnight speeds

Visited three detector stations with UW ALEDA tool for calibrating loop detectors

Stations visited: I-5 NB – Multnomah

High number of readings with occupancy > 95% I-5 NB Terwilliger

Low maximum occupancy I-5 NB OR 217/Kruse Way

Low overnight speeds

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I-5 NB Multnomah BlvdI-5 NB Multnomah Blvd

Lane 1 Lane 2 Lane 3

Sept

19,

2007

Sept

20,

2007

Lane 1 Lane 2 Lane 3

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I-5 NB Terwilliger BlvdI-5 NB Terwilliger Blvd

Sept 19, 2007 - Before

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I-5 NB Terwilliger BlvdI-5 NB Terwilliger Blvd

Sept 20, 2007 – Day of Visit

Sept 19, 2007 – Day of Visit

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I-5 NB Terwilliger BlvdI-5 NB Terwilliger Blvd

Sept 21, 2007 - After

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I-5 NB OR 217/Kruse WayI-5 NB OR 217/Kruse Way

January 17, 2008; Lane 2

January 17, 2008; Lane 3

Sept 18, 2007; Lane 2 Sept 18, 2007; Lane 3

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ODOT ATMS Communication FailuresODOT ATMS Communication Failures

Communication failure is a second major cause of loop detector data errors.

Look for detectors reporting ‘communication failure’ and detectors reporting ‘no traffic’ during congested periods

Communication failures communicated to ODOT subsequently fixed

Communication failure is a second major cause of loop detector data errors.

Look for detectors reporting ‘communication failure’ and detectors reporting ‘no traffic’ during congested periods

Communication failures communicated to ODOT subsequently fixed

8%

5%

14%

1%

0%

2%

4%

6%

8%

10%

12%

14%

16%

January-06 January-07

Detectors with > 10% No Traffic Readings

Detectors with > 5% Communication Failure Readings

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0% 10% 20% 30% 40% 50% 60% 70%

9-24

9-25

9-26

9-27

9-28

10-1

10-2

10-3

10-4

10-5

Communication Failures (%)

I-205 NB, Pre-Timed, PM

Division

Powell

Foster

Johnson Creek

Sunnyside

Sunnybrook

Lawnfield

Clackamas Hwy

Gladstone

0% 10% 20% 30% 40% 50% 60% 70%

9-10

9-11

9-12

9-13

9-14

9-17

9-18

9-19

9-20

9-21

Communication Failures (%)

I-205 NB, SWARM, PM

Division

Powell

Foster

Johnson Creek

Sunnyside

Sunnybrook

Lawnfield

Clackamas Hwy

Gladstone

Impact of Adaptive Ramp MeteringImpact of Adaptive Ramp MeteringImpact of Adaptive Ramp MeteringImpact of Adaptive Ramp Metering

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ConclusionsConclusions

Data quality is crucial to transportation data archives

Detectors require regular maintenance; limited maintenance resources

Need automated process to detect and report malfunctioning detectors

Requires communication between researchers and maintenance staff

Desire mapping between data anomalies and problems in the field

Data quality is crucial to transportation data archives

Detectors require regular maintenance; limited maintenance resources

Need automated process to detect and report malfunctioning detectors

Requires communication between researchers and maintenance staff

Desire mapping between data anomalies and problems in the field

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AcknowledgementsAcknowledgements

National Science Foundation (PORTAL)

Oregon Transportation Research Education and Consortium

TransPORT Oregon DOT Yinhai Wang and Num

Cheevarunothai University of Washington

National Science Foundation (PORTAL)

Oregon Transportation Research Education and Consortium

TransPORT Oregon DOT Yinhai Wang and Num

Cheevarunothai University of Washington

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Thank You!www.its.pdx.edu

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Bonus!Bonus!

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Bonus!Bonus!