USING Pe MS DATA TO EMPIRICALLY DIAGNOSE FREEWAY

USING Pe. MS DATA TO EMPIRICALLY DIAGNOSE FREEWAY BOTTLENECK LOCATIONS IN ORANGE COUNTY, CALIFORNIA Robert L. Bertini Portland State University TRB 84 th Annual Meeting Washington D. C. January 9 -13, 2005 Aaron M. Myton Oregon Department of Transportation

Objectives • • Identify Freeflow a. Congested Conditions Determine Bottleneck Locations Measure Queue Discharge Features Conclusions

Background • • Foundation for Understanding Freeway Operations Queues Cause Delays Loop Detectors Good Data Source Previous Studies – Throughput Increase 2 -5% Prior To Queue – Diverge Bottleneck Identified • Pe. MS Provides Opportunity for Detailed Data Analysis

LEGEND Site Map 110 10 30 20 Irvine Center Dr. Post-mile Hwy. 133 40 Travel Direction 50 Sand Canyon Ave. 60 70 80 University Dr. 90 100 110 N 120 130 140 Culver Dr. • Four Northbound Lanes • One Northbound HOV Lane • Freeway Ramps Between Stations, Except 100/110 Loop Detector Station Number

Bottleneck Definition • Queue upstream • Freely-flowing traffic downstream • Temporally and spatially variable

Data • Freeway Performance Monitoring System (Pe. MS) – http: //pems. eecs. berkeley. edu/Public • • • Single Inductive Loops Vehicle Occupancy and Count Data Aggregated in 30 -sec. Intervals On-Ramp/Off-Ramp Data Not Available Monday June 1, 1998

Methodology • Cumulative Curves – Vehicle Count & Occupancy • Oblique Plots N and T

Analysis Station 140 130 120 5. 60 Culver Dr. 110 100 4. 60 Post mile 90 80 University Dr. 3. 60 70 60 Sand Canyon Ave 2. 60 50 40 1. 60 Hwy. 133 30 20 0. 60 7: 00 Travel Direction 10 7: 30 8: 00 Time, t 8: 30 9: 00 Irvine Center Dr.

8130 9762 Station 70 – Loops 1 -4 Oblique N and T Station 140 130 120 Culver Dr. 110 100 U Q 90 80 University Dr. 70 60 50 40 Sand Canyon Ave Travel Direction Hwy. 133 30 7: 41: 30 SEGMENT # 20 NO QUEUE 10 QUEUE Irvine Center Dr.

Station 140 130 120 5. 60 Culver Dr. 110 100 4. 60 Post mile 90 80 University Dr. 3. 60 70 60 Sand Canyon Ave 2. 60 50 40 1. 60 Hwy. 133 30 20 0. 60 7: 00 Travel Direction 10 7: 30 8: 00 Time, t 8: 30 9: 00 Irvine Center Dr.

Station 60 – Loops 1 -4, Oblique N and T Station 140 130 120 Culver Dr. 110 100 U Q 90 80 University Dr. 70 60 50 40 Sand Canyon Ave Travel Direction Hwy. 133 30 SEGMENT # NO QUEUE 20 10 Irvine Center Dr.

Station 140 130 120 5. 60 Culver Dr. 110 100 4. 60 Post mile 90 80 University Dr. 3. 60 70 60 Sand Canyon Ave 2. 60 50 40 1. 60 Hwy. 133 30 20 0. 60 7: 00 Travel Direction 10 7: 30 8: 00 Time, t 8: 30 9: 00 Irvine Center Dr.

Queue 7 5. 60 Station 140 LEGEND Queue - Activation Queue - Deactivation 130 120 Queue 5 Queue 3 Queue 8 Queue 9 4. 60 Culver Dr. 110 100 Post mile Queue 10 3. 60 90 80 Queue 6 Queue 2 University Dr. 70 60 Queue 1 Queue 4 2. 60 50 40 1. 60 Travel Direction Hwy. 133 30 20 0. 60 7: 00 Sand Canyon Ave 10 7: 30 8: 00 Time, t 8: 30 9: 00 Irvine Center Dr.

Results

Conclusions • • • Ten Queues Formed at Five Locations Flow Reduction of 3 -15% No Queue in HOV Lanes Bottlenecks Typically Activated Near Ramps No Speed Threshold Needed

Future Research • Study site on different days • Manual replication of procedure • Develop semi-automated method

Acknowledgements • Prof. Pravin Varaiya and Prof. Alexander Skabardonis, U. C. Berkeley • Dr. Karl Petty, Berkeley Transportation Systems • Pherak Hay, Vu Mai, and Roger Lindgren

Q SEGMENT # 7: 41: 30 U 8130 9762 Station 70 – Loops 1 -4 Oblique N and T NO QUEUE

Station 60 – Loops 1 -4, Oblique N and T U Q SEGMENT # NO QUEUE