1 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Robert L. Bertini, Rafael J. Fernández-Moctezuma, Jerzy Wieczorek, Huan Li, Portland State University 15th World Congress on ITS New York City, NY November 17, 2008

2 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon PORTAL database Loop Detector Data 20 s count, lane occupancy, speed from 500 detectors (1.2 mi spacing) Incident Data 140,000 since 1999 Weather Data VMS Data 19 VMS since 1999 Data Archive Days Since July 2004 About 300 GB 4.2 Million Detector Intervals Bus Data 1 year stop level data 140,000,000 rows

3 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Objectives How can we automate bottleneck detection? How can we analyze the resulting detected bottlenecks? How can we automate bottleneck detection? How can we analyze the resulting detected bottlenecks?

4 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon What is a Bottleneck? Queueing upstreamQueueing upstream Freely-flowing downstreamFreely-flowing downstream Temporal and spatial variationTemporal and spatial variation Queued Unqueued Bottleneck Detectors

5 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Why study bottlenecks? Find and rank recurrent bottlenecks (via data archive)  Planners know where to focus congestion-reduction efforts Detect bottlenecks in real time  Improve incident detection and travel time predictions Find and rank recurrent bottlenecks (via data archive)  Planners know where to focus congestion-reduction efforts Detect bottlenecks in real time  Improve incident detection and travel time predictions

6 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Research objectives Refine an algorithm to systematically detect freeway bottlenecks, and quantify and visualize their impactsRefine an algorithm to systematically detect freeway bottlenecks, and quantify and visualize their impacts Implement this tool in PORTAL, our continuously-updated transportation data archiveImplement this tool in PORTAL, our continuously-updated transportation data archive Refine an algorithm to systematically detect freeway bottlenecks, and quantify and visualize their impactsRefine an algorithm to systematically detect freeway bottlenecks, and quantify and visualize their impacts Implement this tool in PORTAL, our continuously-updated transportation data archiveImplement this tool in PORTAL, our continuously-updated transportation data archive

7 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Reading a contour plot Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

8 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Reading a contour plot Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

9 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Reading a contour plot Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

10 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Contour plots in real time ? Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

11 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Mockup of desired tool Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

12 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Data I-5 Northbound corridor has best loop detector coverage: 23 detectors over 24 miles, giving 1.1 mi average detector spacingI-5 Northbound corridor has best loop detector coverage: 23 detectors over 24 miles, giving 1.1 mi average detector spacing Chose 5 representative days for initial testingChose 5 representative days for initial testing Averaged data across all 3 lanes, removed bad detectors, and imputed missing valuesAveraged data across all 3 lanes, removed bad detectors, and imputed missing values I-5 Northbound corridor has best loop detector coverage: 23 detectors over 24 miles, giving 1.1 mi average detector spacingI-5 Northbound corridor has best loop detector coverage: 23 detectors over 24 miles, giving 1.1 mi average detector spacing Chose 5 representative days for initial testingChose 5 representative days for initial testing Averaged data across all 3 lanes, removed bad detectors, and imputed missing valuesAveraged data across all 3 lanes, removed bad detectors, and imputed missing values MP 308 MP 284

13 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Our starting point Based on a California field experimentBased on a California field experiment Using 5-minute aggregated data, declare a bottleneck between two detectors in a given time period if:Using 5-minute aggregated data, declare a bottleneck between two detectors in a given time period if: Speed difference across bottleneck is > 20 mph, andSpeed difference across bottleneck is > 20 mph, and Upstream speed is < 40 mphUpstream speed is < 40 mph “Sustained bottlenecks” filter:“Sustained bottlenecks” filter: Remove outliers with too few “neighbors”Remove outliers with too few “neighbors” Fill in any small gaps within bottlenecksFill in any small gaps within bottlenecks Based on a California field experimentBased on a California field experiment Using 5-minute aggregated data, declare a bottleneck between two detectors in a given time period if:Using 5-minute aggregated data, declare a bottleneck between two detectors in a given time period if: Speed difference across bottleneck is > 20 mph, andSpeed difference across bottleneck is > 20 mph, and Upstream speed is < 40 mphUpstream speed is < 40 mph “Sustained bottlenecks” filter:“Sustained bottlenecks” filter: Remove outliers with too few “neighbors”Remove outliers with too few “neighbors” Fill in any small gaps within bottlenecksFill in any small gaps within bottlenecks

14 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon False RateMax Upstream Speed Min Speed Differential Success and False Alarm Rate Tables Success RateMax Upstream Speed Min Speed Differential

15 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Success rate over all 5 days (using sustained filter)

16 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Success rate over all 5 days (using sustained filter)

17 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Success rate over all 5 days (using sustained filter)

18 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Success rate over all 5 days (using sustained filter)

19 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Success rate over all 5 days (using sustained filter)

20 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon False alarm rate over all 5 days (using sustained filter)

21 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon False alarm rate over all 5 days (using sustained filter)

22 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon False alarm rate over all 5 days (using sustained filter)

23 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon False alarm rate over all 5 days (using sustained filter)

24 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon False alarm rate over all 5 days (using sustained filter)

25 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Bottleneck detection results Optimized parameter values for our chosen Portland freeway corridorOptimized parameter values for our chosen Portland freeway corridor Validated this method on Oregon data as a good start:Validated this method on Oregon data as a good start: It successfully finds 75% of bottlenecksIt successfully finds 75% of bottlenecks Only 20% of detections are false alarmsOnly 20% of detections are false alarms Optimized parameter values for our chosen Portland freeway corridorOptimized parameter values for our chosen Portland freeway corridor Validated this method on Oregon data as a good start:Validated this method on Oregon data as a good start: It successfully finds 75% of bottlenecksIt successfully finds 75% of bottlenecks Only 20% of detections are false alarmsOnly 20% of detections are false alarms

26 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Bottleneck analysis tools Find entire congested area upstream of the bottleneck:Find entire congested area upstream of the bottleneck: estimate queue propagation speedestimate queue propagation speed calculate costs of delay, emissions, etccalculate costs of delay, emissions, etc Process historical data and find prior probabilities to improve real-time detectionProcess historical data and find prior probabilities to improve real-time detection Find entire congested area upstream of the bottleneck:Find entire congested area upstream of the bottleneck: estimate queue propagation speedestimate queue propagation speed calculate costs of delay, emissions, etccalculate costs of delay, emissions, etc Process historical data and find prior probabilities to improve real-time detectionProcess historical data and find prior probabilities to improve real-time detection

27 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Congestion tracking Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

28 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Congestion tracking Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

29 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Queue propagation speeds Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP mph 14.1 mph 7.66 mph

30 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Delay (in vehicle-hrs) Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP veh-hrs 1569 veh-hrs veh-hrs

31 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Congestion tracking Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

32 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Congestion tracking Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

33 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Congestion tracking Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

34 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Congestion tracking Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

35 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Congestion Tracking: 90% Of Days Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

36 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Congestion Tracking: 75% Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

37 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Congestion Tracking: 50% Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

38 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Congestion tracking: rarest 10% Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

39 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Mockup of desired tool Interstate bridge MP 308 I-405 MP 304 I-405 MP 300 OR-217 MP 292 I-205 MP 288 I-84 MP 302

40 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Next steps Set parameters for remaining corridors; implement into PORTAL; solicit feedbackSet parameters for remaining corridors; implement into PORTAL; solicit feedback Improve detection algorithm: incorporate weather conditions, occupancy/flow data, historical knowledge, etc.Improve detection algorithm: incorporate weather conditions, occupancy/flow data, historical knowledge, etc. Distinguish incidents from recurrent congestion; rank the latter on Portland’s freewaysDistinguish incidents from recurrent congestion; rank the latter on Portland’s freeways Set parameters for remaining corridors; implement into PORTAL; solicit feedbackSet parameters for remaining corridors; implement into PORTAL; solicit feedback Improve detection algorithm: incorporate weather conditions, occupancy/flow data, historical knowledge, etc.Improve detection algorithm: incorporate weather conditions, occupancy/flow data, historical knowledge, etc. Distinguish incidents from recurrent congestion; rank the latter on Portland’s freewaysDistinguish incidents from recurrent congestion; rank the latter on Portland’s freeways

41 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon AcknowledgmentsAcknowledgments Oregon Department of TransportationOregon Department of Transportation Federal Highway AdministrationFederal Highway Administration TriMetTriMet The City of Portland, ORThe City of Portland, OR National Science FoundationNational Science Foundation CONACYT (Mexico)CONACYT (Mexico) TransPort ITS CommitteeTransPort ITS Committee Oregon Department of TransportationOregon Department of Transportation Federal Highway AdministrationFederal Highway Administration TriMetTriMet The City of Portland, ORThe City of Portland, OR National Science FoundationNational Science Foundation CONACYT (Mexico)CONACYT (Mexico) TransPort ITS CommitteeTransPort ITS Committee Visit PORTAL Online:

42 Using Archived ITS Data to Automatically Identify Freeway Bottlenecks in Portland, Oregon Thank You!