CTS Transportation Seminar Series, January 13, 2006 Aaron Breakstone

January 13, 2006CTS Transportation Seminar Series

Using Ground Truth Geospatial Data to Validate Advanced Traveler Information Systems Freeway Travel Time Messages

CTS Transportation Seminar Series, January 13, 2006

Aaron Breakstone Master of Urban and Regional Planning CandidatePortland State University

Chris Monsere, Ph.D., P.E.Research Assistant Professor Portland State University

Robert L. Bertini, Ph.D., P.E.Associate ProfessorDirector, Center for Transportation StudiesPortland State University


Outline

• Project Overview

• Summary of Test Area

• Experimental Design

• Data Collection

• Data Comparison

• Results

• Next Steps


Project Overview

Goals

1. Evaluate Oregon Department of Transportation (ODOT)’s travel time estimating and reporting capabilities

2. Identify locations where additional detectors might improve estimates


Project Overview

• ODOT Region 1 Traffic Management Operations Center (TMOC) – 485 inductive loop detectors – Advanced Traveler

Information Systems (ATIS): www.TripCheck.com

– 19 dynamic message signs (DMS) 3 display travel times


Project Overview

• Funded by NSF• Direct fiber-optic

connection between ODOT and PSU

• 20-second loop detector data– Volume– Speed– Occupancy

• Customized travel time area

Portland Regional Transportation Archive Listing (PORTAL)

http://portal.its.pdx.edu


Outline




• Data Collection

• Data Comparison

• Results

• Next Steps


Summary of Test Area

• 15 directional freeway links– I-5 (6)– I-205 (3) – I-84 (2)– US-26 (2)– OR-217 (2)

Downtown Portland


Outline




• Data Collection

• Data Comparison

• Results

• Next Steps


Experimental Design• Analysis of PORTAL

estimates to determine required number of runs

• Data collection plan– 5-10 runs required for

most links– 4 routes designed– Transitional periods

targeted– Groups with 5-7 minute

headways– Standard probe vehicle

instructions

217 Southbound: US26 Interchange to I-5 Interchange [Link 9]

0

10

20

30

40

50

60

0:00 2:00 4:00 6:00 8:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 0:00

Time

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lativ

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Outline




• Data Collection

• Data Comparison

• Results

• Next Steps


Data Collection• Hardware

– Palm handheld computers

– Magellan GPS devices

• Software– ITS-GPS

Free Available at www.its.pdx.edu

• Individual runs and groups of probe vehicles

• Variety of traffic conditions


Data Collection• 87 probe vehicle runs• 904 minutes (~15 hours) of collection time• 516 miles of data• 12 drivers• 7 daysdate time elapsed latitude longitude dist mi vel mi/h

2005.04.08 16:17:12 3 45.50830 -122.66865 0.036 43.0982005.04.08 16:17:15 3 45.50865 -122.66806 0.037 44.9632005.04.08 16:17:18 3 45.50902 -122.66749 0.038 45.1932005.04.08 16:17:21 3 45.50944 -122.66705 0.036 43.2472005.04.08 16:17:24 3 45.50995 -122.66680 0.037 44.7582005.04.08 16:17:27 3 45.51050 -122.66676 0.038 45.7102005.04.08 16:17:30 3 45.51106 -122.66690 0.039 47.1882005.04.08 16:17:33 3 45.51161 -122.66719 0.041 48.6672005.04.08 16:17:36 3 45.51222 -122.66750 0.045 53.7452005.04.08 16:17:39 3 45.51289 -122.66770 0.047 56.8142005.04.08 16:17:42 3 45.51360 -122.66776 0.049 59.034


Outline




• Data Collection

• Data Comparison

• Results

• Next Steps


Data Comparison• Probe data

– Individual runs downloaded

– Runs plotted on freeway network map showing link endpoints

– Pertinent data segments extracted

last point on Link 9

last point on Link 2

first point on Link 3


Data Comparison• Detector data

– Assignment of influence areas1. Midpoint method

2. ODOT modified midpoint method

– Aggregation1. Nearest 20-second interval

• e.g. 9:15:34 9:15:20

2. Average of nearest interval and 1 minute before

3. Average of nearest interval and 3 minutes before


Outline




• Data Collection

• Data Comparison

• Results

• Next Steps


Results• ATMS estimates reasonably accurate

P- Value -Statistical Significance

Link Number Midpoint ODOTMidpt -1

minMidpt -3

minODOT -1

minODOT -3

minLINK 2 - I-5 NB 0.073 0.103 0.034 0.071 0.038 0.079LINK 3 - I-5 NB 0.272 0.012 0.214 0.202 0.010 0.035LINK 4 - I-5 NB 0.651 0.665 0.545 0.287 0.560 0.301LINK 5 - I-5 SB 0.470 0.470 0.503 0.256 0.503 0.256LINK 6 - I-5 SB 0.435 0.095 0.676 0.605 0.052 0.045LINK 7 - I-5 SB 0.009 0.009 0.021 0.016 0.021 0.016LINK 8 - OR-217 NB 0.016 0.011 0.012 0.024 0.009 0.011LINK 9 - OR-217 SB 0.381 0.040 0.199 0.159 0.146 0.205LINK 10 - I-205 NB 0.532 0.460 0.277 0.040 0.896 0.965LINK 12 - I-205 SB 0.537 0.020 0.478 0.731 0.003 0.003LINK 13 - I-84 EB 0.273 0.070 0.518 0.402 0.098 0.077LINK 14 - I-84 WB 0.736 0.736 0.754 0.530 0.754 0.530LINK 16 - US 26 EB 0.026 0.026 0.009 0.012 0.009 0.012LINK 17 - US 26 WB 0.013 0.013 0.014 0.012 0.013 0.011


Results• ATMS estimates reasonably accurate

Run 1

303.5

304.0

304.5

305.0

305.5

306.0

306.5

307.0

307.5

308.0

8:03:00 8:05:00 8:07:00 8:09:00 8:11:00 8:13:00 8:15:00 8:17:00 8:19:00 8:21:00

Time

Mile

po

st

Run 9

0.3

0.8

1.3

1.8

2.3

2.8

3.3

16:30:00 16:32:00 16:34:00 16:36:00 16:38:00 16:40:00 16:42:00 16:44:00 16:46:00 16:48:00

Time

Mile

post

Probe Vehicle

Other Projections

Projected Trajectory


Results• Detector density and location critical

Run 7

292.3

293.3

294.3

295.3

296.3

297.3

298.3

299.3

300.3

8:05:00 8:10:00 8:15:00 8:20:00 8:25:00 8:30:00

Time

Mile

post

Run 1

303.5

304.0

304.5

305.0

305.5

306.0

306.5

307.0

307.5

308.0

8:06:00 8:08:00 8:10:00 8:12:00 8:14:00 8:16:00

Time

Mile

post

Run 6

68.9

69.4

69.9

70.4

70.9

71.4

71.9

72.4

72.9

8:17:00 8:18:30 8:20:00 8:21:30 8:23:00 8:24:30 8:26:00 8:27:30

Time

Mile

post

}~ 11 minutes (8 miles)

}~ 2 minutes (4 mi.)

Probe

Projection

Influence Area Limit


Results• Incidents difficult to capture

Run 1

69.7

70.2

70.7

71.2

71.7

72.2

72.7

73.2

73.7

16:26:00 16:28:00 16:30:00 16:32:00 16:34:00 16:36:00 16:38:00 16:40:00 16:42:00

Time

Mile

post

Run 3

0.3

1.1

1.9

2.7

3.5

4.3

5.1

5.9

6.7

8:18:00 8:23:00 8:28:00 8:33:00 8:38:00 8:43:00 8:48:00 8:53:00 8:58:00

Time

Mile

post


Results• No uniform difference between methods• Aggregation improves accuracy

Travel Time Observations (95% CI)

0.00

1.00

2.00

3.00

4.00

5.00

6.00

Probe Midpoint ODOT Midpt -1

min

Midpt -3

min

ODOT -1

min

ODOT -3

min

Travel Time Differences

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

Midpoint ODOT Midpt -1

min

Midpt -3

min

ODOT -1

min

ODOT -3

min

AVG MIN MAX

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5

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15

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35

0 5 10 15 20 25 30 35

Observed Probe Vehicle Travel Tim e

Est

imat

ed T

rave

l Tim

e

(a) Nearest 20 second estimate

0

5

10

15

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25

30

35

0 5 10 15 20 25 30 35

Observed Probe Vehicle Trave l Tim e

Est

imat

ed T

rave

l Tim

e

0

5

10

15

20

25

30

35

0 5 10 15 20 25 30 35

Observed Probe Vehicle Travel Tim e

Est

imat

ed T

rave

l Tim

e

(b) Average of previous 1 minute (c) Average of 3 previous minutes


ResultsCandidate locations for increased detection

– Recurring congestion– Detector spacing > 1 mile

1. Hwy 217 NB at MP 3.22. US-26 EB at MP 703. US-26 WB at MP 694. US-26 WB at MP 705. I-5 NB at MP 298.56. I-5 SB at MP 306.57. I-84 EB at MP 2.0


Outline




• Data Collection

• Data Comparison

• Results

• Next Steps


Next Steps

• More data– Incidents– Transitions

• Different algorithms– Historical data– Other detectors (e.g. Coifman)


Acknowledgements

• Oregon Department of Transportation– Stacy Shetler– Galen McGill– Dennis Mitchell– Jack Marchant

• Castle Rock

Consultants– Dean Deeter

• Student drivers

CTS Transportation Seminar Series, January 13, 2006 Aaron Breakstone

Documents

Transcript of CTS Transportation Seminar Series, January 13, 2006 Aaron Breakstone