USING PeMS DATA TO EMPIRICALLY DIAGNOSE FREEWAY BOTTLENECK LOCATIONS
IN ORANGE COUNTY, CALIFORNIA
Robert L. BertiniPortland State University
Aaron M. MytonOregon Department of
Transportation
TRB 84th Annual Meeting
Washington D.C.
January 9-13, 2005
Objectives
• Identify Freeflow Congested Conditions
• Determine Bottleneck Locations
• Measure Queue Discharge Features
• Conclusions
• 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
• PeMS Provides Opportunity for Detailed Data Analysis
Background
Cul
ver D
r.
Uni
vers
ity D
r.
Sand
Can
yon
Ave
.
Hw
y. 1
33
Irvin
e C
ente
r Dr.
Trav
el D
irect
ion
130
110
100
90 80 70 60 50 40 30 20 10
Site Map Loop DetectorStation Number
L E G E N D
110
120
• Four Northbound Lanes
• One Northbound HOV Lane
• Freeway Ramps Between Stations, Except 100/110
140
N
Post-mile
Bottleneck Definition
Queued Unqueued
Bottleneck
D e te c to rs
• Queue upstream
• Freely-flowing traffic downstream
• Temporally and spatially variable
Data• Freeway Performance Monitoring System (PeMS)
– 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
Analysis
Time, t
Culver Dr.
University Dr.
Sand Canyon Ave.
Hwy. 133
Irvine Center Dr.
Travel Direction
0.60
1.60
2.60
3.60
4.60
5.60
7:00 7:30 8:00 8:30 9:00
Po
st m
ile
Station140
130120
110100
9080
70
60
50
40
30
20
10
-53500
-53000
-52500
-52000
-51500
-51000
-505007:
00
8:00
9:00Time, t
N(7
0,t)
- q0t
', q
0 =
9500
vph
-14000
-13800
-13600
-13400
-13200
-13000
-12800
-12600
T(70
,t) -
b0t
', b
0 =
2400
sec
onds
per
hou
r
T(70,t) - b0(70)t'
N(70,t) - q0(70)t'
1 2 3 4 75 6
1863
9206
7:14
:00
2341
3368
2509
4663
2595 28
81
1403
1017
2
8255
8958
6480
9146
8010
6772
8
7:33
:00
8:39
:00
8:49
:00
8:50
:00
8:57
:00
9:01
:00
7:51
:30
8:16
:30
9 10 11
3578
2705
3199
8880
9367
8904
3271
8629
SEGMENT #
QUEUENO QUEUE
7:41
:30
8130
9762
QU
Culver Dr.
University Dr.
Sand Canyon Ave.
Hwy. 133
Irvine Center Dr.
Travel Direction
Station140
130120
110100
9080
70
60
50
40
30
20
10
Station 70 – Loops 1-4 Oblique N and T
Time, t
Culver Dr.
University Dr.
Sand Canyon Ave.
Hwy. 133
Irvine Center Dr.
Travel Direction
0.60
1.60
2.60
3.60
4.60
5.60
7:00 7:30 8:00 8:30 9:00
Po
st m
ile
Station140
130120
110100
9080
70
60
50
40
30
20
10
-47000
-46500
-46000
-45500
-45000
-44500
-440007:
00
8:00
9:00
Time, t
N(6
0,t)
- q0t
', q
0 =
8500
vph
-11800
-11600
-11400
-11200
-11000
-10800
-10600
-10400
T(60
,t) -
b0t
', b
0 =
2000
sec
onds
per
hou
r
T(60,t) - b0(60)t'
N(60,t) - q0(60)t'15
1085
20
1 2 4 5 6 7 8
2010 25
82
3094
2438 16
31
1085
9525 95
60
7809
8379
7649
6103
7:14
:00
7:31
:30
7:34
:30
8:22
:00
8:39
:30
9:01
:00
2838
7906
8289
7511
2240
3172
9 10
7:54
:00
8:01
:00
3
7:22
:00
9208
1962
SEGMENT #
QUEUENO QUEUE
QU
Culver Dr.
University Dr.
Sand Canyon Ave.
Hwy. 133
Irvine Center Dr.
Travel Direction
Station140
130120
110100
9080
70
60
50
40
30
20
10
Station 60 – Loops 1-4, Oblique N and T
Time, t
Culver Dr.
University Dr.
Sand Canyon Ave.
Hwy. 133
Irvine Center Dr.
Travel Direction
0.60
1.60
2.60
3.60
4.60
5.60
7:00 7:30 8:00 8:30 9:00
Po
st m
ile
Station140
130120
110100
9080
70
60
50
40
30
20
10
Time, t
Culver Dr.
University Dr.
Sand Canyon Ave.
Hwy. 133
Irvine Center Dr.
Travel Direction
0.60
1.60
2.60
3.60
4.60
5.60
7:00 7:30 8:00 8:30 9:00
Po
st m
ile
Queue 1
Queue 2
Queue 4
Queue 5
Queue 7
Queue 3
Queue 6
Queue 9
Queue 10
Queue 8
Station140
130120
110100
9080
70
60
50
40
30
20
10
Queue - ActivationQueue - Deactivation
LEGEND
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
Station 50, Occupancy
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
12:00 AM 2:00 AM 4:00 AM 6:00 AM 8:00 AM 10:00 AM 12:00 PM 2:00 PM 4:00 PM 6:00 PM 8:00 PM 10:00 PM 12:00 AM
Time
Occ
up
ancy
Station 40, Occupancy
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
12:00 AM 2:00 AM 4:00 AM 6:00 AM 8:00 AM 10:00 AM 12:00 PM 2:00 PM 4:00 PM 6:00 PM 8:00 PM 10:00 PM 12:00 AM
Time
Occ
up
ancy
-53500
-53000
-52500
-52000
-51500
-51000
-50500
7:00
8:00
9:00
Time, t
N(7
0,t)
- q
0t',
q0
= 9
500
vph
-14000
-13800
-13600
-13400
-13200
-13000
-12800
-12600
T(7
0,t)
- b
0t',
b0
= 2
400
seco
nd
s p
er h
ou
r
T(70,t) - b0(70)t'
N(70,t) - q0(70)t'
1 2 3 4 75 6
1863
9206
7:14
:00
2341
3368
2509
4663
2595 28
81
1403
1017
2
8255
8958
6480
9146
8010
6772
8
7:33
:00
8:39
:00
8:49
:00
8:50
:00
8:57
:00
9:01
:00
7:51
:30
8:16
:30
9 10 11
3578
2705
3199
8880
9367
8904
3271
8629
SEGMENT #
QUEUENO QUEUE
7:41
:30
8130
9762
QU
Station 70 – Loops 1-4 Oblique N and T
-47000
-46500
-46000
-45500
-45000
-44500
-44000
7:00
8:00
9:00
Time, t
N(6
0,t)
- q
0t',
q0
= 8
500
vph
-11800
-11600
-11400
-11200
-11000
-10800
-10600
-10400
T(6
0,t)
- b
0t',
b0
= 2
000
seco
nd
s p
er h
ou
r
T(60,t) - b0(60)t'
N(60,t) - q0(60)t'
1510
8520
1 2 4 5 6 7 8
2010 25
82
3094
2438 16
31
1085
9525 95
60
7809
8379
7649
6103
7:14
:00
7:31
:30
7:34
:30
8:22
:00
8:39
:30
9:01
:00
2838
7906
8289
7511
2240
3172
9 10
7:54
:00
8:01
:00
3
7:22
:00
9208
1962
SEGMENT #
QUEUENO QUEUE
QU
Station 60 – Loops 1-4, Oblique N and T