200th Seminar! Travel Time Estimation for Traffic Management and Traveler Information
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Transcript of 200th Seminar! Travel Time Estimation for Traffic Management and Traveler Information
1Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Robert L. BertiniRobert L. BertiniDepartment of Civil and Environmental EngineeringDepartment of Civil and Environmental EngineeringNohad A. Toulan School of Urban Studies and PlanningNohad A. Toulan School of Urban Studies and PlanningPortland State UniversityPortland State UniversityOregon Transportation Research and Education ConsortiumOregon Transportation Research and Education ConsortiumTransportation Seminar No. 200 Transportation Seminar No. 200 •• April 4, 2008April 4, 2008
Travel Time Estimation for Travel Time Estimation for Traffic Management and Traffic Management and Traveler InformationTraveler Information
2Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
ObjectivesObjectives
Travel time visualizationsTravel time fundamentalsPrevious researchFramework for sensor spacingAnalytical tool for sensor spacingFuture researchSeminar perspectives
Travel time visualizationsTravel time fundamentalsPrevious researchFramework for sensor spacingAnalytical tool for sensor spacingFuture researchSeminar perspectives
3Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
What Can I Do With Travel Time?What Can I Do With Travel Time?
Travel time is fundamentalCan be used to generate other thingsTravel time is multimodal
Travel time is fundamentalCan be used to generate other thingsTravel time is multimodal
4Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
What Can I Do With Travel Time?What Can I Do With Travel Time?
Measure itGuess itReport itPredict itForecast it
Measure itGuess itReport itPredict itForecast it
5Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
If I Get It Wrong?If I Get It Wrong?
Annoy travelersDestroy confidence in systemIncrease congestionWorsen safetyDamage air qualityIncrease fuel consumption
Annoy travelersDestroy confidence in systemIncrease congestionWorsen safetyDamage air qualityIncrease fuel consumption
6Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
How Can I Affect Travel Time?How Can I Affect Travel Time?
Increase/decrease mean valueIncrease/decrease variabilityAffect comparison between modes
Increase/decrease mean valueIncrease/decrease variabilityAffect comparison between modes
7Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
ContextContextContext
“Prediction is very difficult, especially about the future.”
—Niels Bohr
8Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Portland Travel TimesPortland Travel TimesPortland Travel Times
9Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
London UndergroundLondon UndergroundLondon Underground
10Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
London UndergroundLondon UndergroundLondon Underground
11Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
2004 Tsunami2004 Tsunami2004 Tsunami
12Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Runoff Travel TimeRunoff Travel TimeRunoff Travel Time
13Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Fire Station Response TimeFire Station Response TimeFire Station Response Time
14Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
New York Commuter RailNew York Commuter RailNew York Commuter Rail
15Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
2004 Tsunami2004 Tsunami2004 Tsunami
Train journey times from Cambridge
16Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Travel time difference train vs. car from Cambridge
17Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
FundamentalsFundamentalsFundamentals
Time
Dis
tan
ce
Slope = Speed
Travel Time
18Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
FundamentalsFundamentalsFundamentals
Time
Dis
tan
ce
Actual Travel Time
Free Flow Travel Time Actual – Free Flow= Delay
19Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Fundamentals – One DetectorFundamentals Fundamentals –– One DetectorOne Detector
Time
Dis
tan
ce
Travel Time
20Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Midpoint MethodMidpoint MethodMidpoint Method
Influence
Area 4Travel Time 4
(at t = 0)
Travel Time 1Influence
Area 1
Travel Time 3
(at t = 0)
Influence
Area 3
Travel Time 2
(at t = 0)
Influence
Area 2
Link Travel Time
(TT1 + TT2 + TT3 + TT4)
21Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Fundamentals – Two DetectorsFundamentals Fundamentals –– Two DetectorsTwo Detectors
Time
Dis
tan
ce
Travel Time
22Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Measurement ParametersMeasurement Parameters
Fixed LocationsStop Watch Method
Detectors (any kind)RF Toll TagsRF “Sign Posts”Video Image (license plate)Volume Based
Fixed TimesGPS + Wireless CommunicationCellular Phone
Fixed LocationsStop Watch Method
Detectors (any kind)RF Toll TagsRF “Sign Posts”Video Image (license plate)Volume Based
Fixed TimesGPS + Wireless CommunicationCellular Phone
23Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Measurement: Fixed LocationsMeasurement: Fixed LocationsMeasurement: Fixed Locations
Time
Dis
tan
ce
x1
x2
Location Time
x1
x2
24Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Measurement: Fixed LocationsMeasurement: Fixed LocationsMeasurement: Fixed LocationsD
ista
nce
x1
x2
Location Time
x1 t1
x2
Time
25Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Measurement: Fixed LocationsMeasurement: Fixed LocationsMeasurement: Fixed LocationsD
ista
nce
x1
x2
Location Time
x1 t1
x2 t2
Time
t1 t2
26Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Measurement: Fixed LocationsMeasurement: Fixed LocationsMeasurement: Fixed LocationsD
ista
nce
x1
x2
Location Time
x1 t1
x2 t2
Time
t1 t2
27Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Measurement: Fixed TimesMeasurement: Fixed TimesMeasurement: Fixed Times
Dis
tan
ce
x1
Time
t1 t2 t3 t4 t5
Time Location
t1 x1
t2
t3
t4
t5
28Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Measurement: Fixed TimesMeasurement: Fixed TimesMeasurement: Fixed Times
Dis
tan
ce
x1
Time
t1 t2 t3 t4 t5
x2
Time Location
t1 x1
t2 x2
t3
t4
t5
29Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Measurement: Fixed TimesMeasurement: Fixed TimesMeasurement: Fixed Times
Dis
tan
ce
x1
Time
t1 t2 t3 t4 t5
x3
x2
Time Location
t1 x1
t2 x2
t3 x3
t4
t5
30Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Measurement: Fixed TimesMeasurement: Fixed TimesMeasurement: Fixed Times
Dis
tan
ce
x1
Time
t1 t2 t3 t4 t5
x4
x3
x2
Time Location
t1 x1
t2 x2
t3 x3
t4 x4
t5
31Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Measurement: Fixed TimesMeasurement: Fixed TimesMeasurement: Fixed Times
Dis
tan
ce
x1
x5
Time
t1 t2 t3 t4 t5
x4
x3
x2
Time Location
t1 x1
t2 x2
t3 x3
t4 x4
t5 x5
32Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Use Counts (TTI Method)Use Counts (TTI Method)Use Counts (TTI Method)
33Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Use Counts (TTI Method)Use Counts (TTI Method)Use Counts (TTI Method)
34Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Flow (vph)
Sp
eed
(m
ph
)
Similar Idea Using Granular DataSimilar Idea Using Granular DataSimilar Idea Using Granular Data
35Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
WSDOT Travel TimesWSDOT Travel TimesWSDOT Travel Times
36Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Data Collection Was DifficultData Collection Was DifficultData Collection Was Difficult
Data CollectionGreenshields, et al., 1947
SpeedometerGreenshields, et al., 1957
37Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Previous Research: LAFSPPrevious Research: LAFSPPrevious Research: LAFSP
38Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Previous: Highway 18Previous: Highway 18Previous: Highway 18
39Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Previous Research: FrontierPrevious Research: FrontierPrevious Research: Frontier
40Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Previous Research: ODOT VMS IPrevious Research: ODOT VMS IPrevious Research: ODOT VMS I
40
15 directional freeway 15 directional freeway linkslinks87 probe runs87 probe runs516 miles/12 drivers516 miles/12 drivers15 hours of data collected15 hours of data collected
41Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Previous Research: ODOT VMS IPrevious Research: ODOT VMS IPrevious Research: ODOT VMS I
0
2
4
6
8
10
12
14
16
18
20
0 2 4 6 8 10 12 14 16 18 20
Probe Travel Time (min)
Estim
ated
Tra
vel T
ime
(min
)Coifman (u/s)Coifman (d/s)MidpointCoifman - MidpointCoifman - DistwtMidpoint - Average
42Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Previous Research: ODOT VMS IPrevious Research: ODOT VMS IPrevious Research: ODOT VMS I
43Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Previous Research: ODOT VMS IPrevious Research: ODOT VMS IPrevious Research: ODOT VMS I
00
2
4
6
8
10
12
14
16
0 2 4 6 8 10 12 14
Bus Travel Time (min)
Estim
ated
Tra
vel T
ime
(min
)Coifman (u/s)Coifman (d/s)MidpointCoifman - MidpointCoifman - Distwt
44Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
ODOT Phase II: TufteODOT Phase II: Tufte
Data quality
Congestion
300 ground truth runs on I-5 and OR 217
Other algorithms
Data quality
Congestion
300 ground truth runs on I-5 and OR 217
Other algorithms
45Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
ODOT Phase IIODOT Phase II
Average error ~5-7%Need for more detection, but where?Average error ~5-7%Need for more detection, but where?
0
5
1015
20
25
30
3540
45
50
<-30 -30-20 -20-10 -10-0 0-10 10-20 20-30 >30% Error
% o
f Run
s
# of Runs - 67
II--5 N5 N
0
10
20
30
40
50
<-30 -30-20 -20-10 -10-0 0-10 10-20 20-30 >30% Error
% o
f Run
s
# of Runs - 60
II--5 S5 S
46Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
MotivationMotivation
Ongoing efforts to improve Ongoing efforts to improve freeway travel time estimatesfreeway travel time estimatesDisplay travel time ranges for key Display travel time ranges for key corridorscorridorsDesire to provide additional Desire to provide additional detectiondetectionNeed for Need for ““optimaloptimal”” decisiondecision--making aidmaking aid
47Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Portland ATMSPortland ATMS
Freeway Surveillance 502 inductive loop detectors~175 stations
Dual loop (act as single loop)1.2 mile average spacingUpstream of on-ramps
135 ramp meters98 CCTV
ATISwww.TripCheck.com
Real-time speed mapStatic CCTV images
18 dynamic message signs (DMS) 3 display travel times
Freeway Surveillance Freeway Surveillance 502 inductive loop detectors502 inductive loop detectors~175 stations~175 stations
Dual loop (act as single loop)Dual loop (act as single loop)1.2 mile average spacing1.2 mile average spacingUpstream of onUpstream of on--rampsramps
135 ramp meters135 ramp meters98 CCTV 98 CCTV
ATISATISwww.TripCheck.comwww.TripCheck.com
RealReal--time speed maptime speed mapStatic CCTV images Static CCTV images
18 dynamic message signs (DMS) 18 dynamic message signs (DMS) 3 display travel times 3 display travel times
48Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Freeway Detector LocationsFreeway Detector LocationsFreeway Detector Locations
49Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Portland Speed/Travel Time InfoPortland Speed/Travel Time InfoPortland Speed/Travel Time Info
50Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Bus/Arterial SpeedsBus/Arterial SpeedsBus/Arterial Speeds
51Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Hypothetical x-t PlaneHypothetical Hypothetical xx--tt PlanePlane
x1MeasuredSpeed
i
Actual Travel TimeFree Flow Travel Time
FreeFlowSpeed
Extrapolated Travel Time
l=
Segm
ent L
ength
x
tExtrapolatedSpeed
Over-prediction
t1 = Time Interval
Delay
52Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Freeway Corridor ExampleFreeway Corridor Example
305.67 Columbia
305
300
295
290
285
4:00
8:00
12:0
0
16:0
0
20:0
0
285.26 Wilsonville
291.00 Carman
298.48 Iowa
302.22 Rose Qtr.
80
60
40
20
0
vfvAC
VMSMP
Time 02/08/07 Northbound I-5
DOWNTOWN
1 mile
A
B
DA C
AC CD
vCD DA
53Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Traffic Flow Relation and DynamicsTraffic Flow Relation and Dynamics
q
k
qC
vf vc
vACqA
A
BC
D
A
B
C
D
A
x
t
vCD
bn
tdeact
vCDvAC
vfDAAC CD
Aassumptions:Aassumptions:
1 mile segment1 mile segmentss ~ 0.1~ 0.1--1.0 mile1.0 mileqqA A = 2000 vph= 2000 vphqqC C = 1800 vph= 1800 vphvvf f = 60 mph= 60 mphvvc c = 30 mph= 30 mphvvCD CD = = --17.1 mph17.1 mphvvAC AC = = --7.5 mph7.5 mph
54Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
0
500
1000
1500
2000
2500
0 50 100 150 200Density (veh/mi)
Flo
w (
veh
/h
r)
qA =2000
qC =1800
vf =60
vc =30vCD = -17.1
D
CB
AvAC = -7.5
55Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
0
500
1000
1500
2000
2500
0 50 100 150 200Density (veh/mi)
Flo
w (
veh
/h
r)
Real data I-5 Macadam2/8/07
56Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Types of TransitionsTypes of TransitionsTypes of Transitions
Time
Dis
tan
ce Frontal stationary
Backwardrecovery
Forwardrecovery
Forward forming
Backwardforming
Rear stationary
57Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Types of TransitionsTypes of TransitionsTypes of Transitions
Time
Dis
tan
ce Frontal stationary
Backwardrecovery
Forwardrecovery
Forward forming
Backwardforming
Rear stationary
58Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
d =
l=
Segm
ent L
ength
x
t
A, D, DA: uncongested C: congested
vf vc
ttf = l/vf ttc = l/vc
Estimation When HomogeneousEstimation When Homogeneous
VHT Actual = VHT EstimatedVHT Actual = VHT Estimated
59Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Types of TransitionsTypes of TransitionsTypes of Transitions
Time
Dis
tan
ce Frontal stationary
Backwardrecovery
Forwardrecovery
Forward forming
Backwardforming
Rear stationary
60Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Types of TransitionsTypes of TransitionsTypes of Transitions
Time
Dis
tan
ce Frontal stationary
Backwardrecovery
Forwardrecovery
Forward forming
Backwardforming
Rear stationary
61Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Types of TransitionsTypes of TransitionsTypes of Transitions
Time
Dis
tan
ce Frontal stationary
Backwardrecovery
Forwardrecovery
Forward forming
Backwardforming
Rear stationary
62Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Traffic Flow Relation and DynamicsTraffic Flow Relation and Dynamics
A
B
C
D
A
x
t
bn
tdeact
vCDvAC
vfDAAC CD
63Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
t
x
svc
vf
tc
vAC
Congestion Signalα = Lag Time
j1
Shockttf
l
z j3
j2
umaxttf
Transition UncongestedTransition Uncongested CongestedCongested
64Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
t
x
svc
vf
tc
vAC
Congestion Signalα = Lag Time
j1
Shockttf
l
z j3
j2
umaxttf
Transition UncongestedTransition Uncongested CongestedCongested
65Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
t
x
svc
vf
tc
vAC
Congestion Signalα = Lag Time
j1
Shockttf
l
z j3
j2
umaxttf
Transition UncongestedTransition Uncongested CongestedCongested
66Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
t
x
svc
vf
tc
vAC
Congestion Signalα = Lag Time
j1
Shockttf
l
z j3
j2
umaxttf
Transition UncongestedTransition Uncongested CongestedCongested
67Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
t
x
svc
vf
tc
vAC
Congestion Signalα = Lag Time
j1
Shockttf
l
z j3
j2
umaxttf
Transition UncongestedTransition Uncongested CongestedCongested
UNDERUNDER OVEROVER
68Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
t
x
svc
vf
tc
vAC
Congestion Signalα = Lag Time
j1
Shockttf
l
z j3
j2
umaxttf
Transition UncongestedTransition Uncongested CongestedCongested
69Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
x
l
s=0.50
x
s=0.25
x
s=0.10
t
l
t
x
s=0.33
Sensor Density Affects Lag TimeSensor Density Affects Lag Time
70Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Transition UncongestedTransition Uncongested CongestedCongested
0.0 0.2 0.4 0.6 0.8 1.0Sensor Spacing (miles)
7.0
7.5
8.0
8.5
9.0
9.5
VHT
Predicted VHT
Actual VHT
71Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Transition UncongestedTransition Uncongested CongestedCongested
-25%
-20%
-15%
-10%
-5%
0%
5%
10%
15%
20%
25%
0.0 0.2 0.4 0.6 0.8 1.0Sensor Spacing (miles)
VHT
Erro
r Error (Penalty)
Error (Absolute Value)
OVER
UNDER
Error (Additive)
72Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Transition UncongestedTransition Uncongested CongestedCongested
-25%
-20%
-15%
-10%
-5%
0%
5%
10%
15%
20%
25%
0.0 0.2 0.4 0.6 0.8 1.0Sensor Spacing (miles)
VHT
Erro
r
7.0
7.5
8.0
8.5
9.0
9.5
VHT
Actual VHT
Error (Additive)
Error (Penalty)
Error (Absolute Value)
Predicted VHT
73Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Traffic Flow Relation and DynamicsTraffic Flow Relation and Dynamics
A
B
C
D
A
x
t
bn
tdeact
vCDvAC
vfDAAC CD
74Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
t
x
s
tr
vCD
Recovery Signalα′ = Lag Time
vc
vf
j1
Wavettc
l
zj3j2
umax
ttf
Transition CongestedTransition Congested UncongestedUncongested
75Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
t
x
s
tr
vCD
Recovery Signalα′ = Lag Time
vc
vf
j1
Wavettc
l
zj3j2
umax
ttf
Transition CongestedTransition Congested UncongestedUncongested
UNDERUNDEROVOV ERER
76Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
t
x
s
tr
vCD
Recovery Signalα′ = Lag Time
vc
vf
j1
Wavettc
l
zj3j2
umax
ttf
Transition CongestedTransition Congested UncongestedUncongested
UNDERUNDEROVEROVER
77Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
t
x
s
tr
vCD
Recovery Signalα′ = Lag Time
vc
vf
j1
Wavettc
l
zj3j2
umax
ttf
Transition CongestedTransition Congested UncongestedUncongested
UNDERUNDEROVOV ERER
78Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Transition CongestedTransition Congested UncongestedUncongested
0.0 0.2 0.4 0.6 0.8 1.0Sensor Spacing (miles)
3.8
3.9
4.0
4.1
4.2
4.3
4.4
4.5
4.6
4.7
VHT
Predicted VHT
Actual VHT
79Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Transition CongestedTransition Congested UncongestedUncongested
-15%
-10%
-5%
0%
5%
10%
15%
20%
25%
30%
35%
0.0 0.2 0.4 0.6 0.8 1.0Sensor Spacing (miles)
VHT
Erro
r
Error (Additive)
Error (Penalty)
Error (Absolute Value)
OVER
UNDER
80Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Transition CongestedTransition Congested UncongestedUncongested
-15%
-10%
-5%
0%
5%
10%
15%
20%
25%
30%
35%
0.0 0.2 0.4 0.6 0.8 1.0Sensor Spacing (miles)
VHT
Erro
r
3.8
3.9
4.0
4.1
4.2
4.3
4.4
4.5
4.6
4.7
VHT
Error (Additive)
Error (Penalty)
Error (Absolute Value)
Predicted VHT
Actual VHT
81Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
0.0 0.2 0.4 0.6 0.8 1.0Sensor Spacing (miles)
2.0
2.5
3.0
3.5
4.0
4.5
5.0
VHT
Actual VHT
Underprediction OnlyUnderprediction Only
Predicted VHT
82Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
15%
16%
17%
18%
19%
20%
21%
0.0 0.2 0.4 0.6 0.8 1.0Sensor Spacing (miles)
VHT
Erro
r Error
Underprediction OnlyUnderprediction Only
83Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
15%
16%
17%
18%
19%
20%
21%
0.0 0.2 0.4 0.6 0.8 1.0Sensor Spacing (miles)
VHT
Erro
r
2.0
2.5
3.0
3.5
4.0
4.5
5.0
VHT
Error
Predicted VHT
Actual VHT
Underprediction OnlyUnderprediction Only
84Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Considering Both TransitionsConsidering Both Transitions
0.0 0.2 0.4 0.6 0.8 1.0Sensor Spacing (miles)
11.1
11.3
11.5
11.7
11.9
12.1
12.3
12.5
12.7
12.9
13.1
VHT
Predicted VHT
Actual VHT
85Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Considering Both TransitionsConsidering Both Transitions
-15%
-10%
-5%
0%
5%
10%
15%
20%
25%
0.0 0.2 0.4 0.6 0.8 1.0Sensor Spacing (miles)
VHT
Erro
r
Error (Additive)
Error (Penalty)
Error (Absolute Value)
86Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Considering Both TransitionsConsidering Both Transitions
-15%
-10%
-5%
0%
5%
10%
15%
20%
25%
0.0 0.2 0.4 0.6 0.8 1.0Sensor Spacing (miles)
VHT
Erro
r
11.1
11.3
11.5
11.7
11.9
12.1
12.3
12.5
12.7
12.9
13.1
VHT
Error (Additive)
Error (Penalty)
Error (Absolute Value)
Predicted VHT
Actual VHT
87Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
t
x
svc
vf
tc
vAC
Congestion Signalttf=α = Lag Time
j1
Shock
l
z j3j2
umaxttf
Detector at End of SectionDetector at End of SectionDetector at End of Section
88Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
t
x
svc
vf
tc
vAC
Congestion Signalttf=α = Lag Time
j1
Shock
l
z j3j2
umaxttf
Detector at End of SectionDetector at End of SectionDetector at End of Section
89Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Effects of Detector at EndEffects of Detector at EndEffects of Detector at End
Regime ACUnderprediction
DetectorLocation
Umax(Min)
Lag Time(Min)
VHT/MilePred
VHT/MileAct
Under %Error
Midpoint 0.56 4.00 2.78 3.55 22%
Downstream 0.11 0.00 0.56 0.59 5%
OverpredictionDetectorLocation
Umax(Min)
Lag Time(Min)
VHT/MilePred
VHT/MileAct
Under %Error
Midpoint 0.56 4.00 4.44 3.95 -13%
Downstream 0.11 0.00 8.89 6.91 -29%
90Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
The FutureThe Future
Better estimates and forecastsFusion of fixed and mobile sourcesUbiquity of integrated information
In-vehicleIn-deviceMultimodal routing/decision-makingCustomizableBetter management
Better estimates and forecastsFusion of fixed and mobile sourcesUbiquity of integrated information
In-vehicleIn-deviceMultimodal routing/decision-makingCustomizableBetter management
91Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Seminar PerspectivesSeminar Perspectives
Inspired by Berkeley’s Transportation Science Seminar, originated by G.F. Newell, 1965
First seminar October 5, 2000, Benefits of Archived ITS Data: Measuring Capacity at a Freeway Bottleneck
200 seminars completed
Began streaming video October 2002: 165available for download and streaming
Began podcasts (mp3) in October 2007: 30podcasts now available
Venue for student/faculty interaction
Strong involvement of transportation community
Inspired by Berkeley’s Transportation Science Seminar, originated by G.F. Newell, 1965
First seminar October 5, 2000, Benefits of Archived ITS Data: Measuring Capacity at a Freeway Bottleneck
200 seminars completed
Began streaming video October 2002: 165available for download and streaming
Began podcasts (mp3) in October 2007: 30podcasts now available
Venue for student/faculty interaction
Strong involvement of transportation community
92Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
PodcastsPodcastsPodcasts
93Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
Seminar PerspectivesSeminar Perspectives
Organized by graduate students?More social interaction before/after?More point/counterpoint?We’re open to other ideas!First air transportation seminar on May 9Other topics we haven’t covered?
Organized by graduate students?More social interaction before/after?More point/counterpoint?We’re open to other ideas!First air transportation seminar on May 9Other topics we haven’t covered?
94Travel Time Estimation for Traffic Management and Traveler InformationTravel Time Estimation for Traffic Management and Traveler Information
AcknowledgementsAcknowledgements
Travel time project teams, past and presentKristin Tufte, Sirisha Kothuri, David Lovell, Ben Zielke, Rafael Fernandez, Ed Anderson Sutti Tantiyanugulchai, Roger Lindgren, Monica LealGalen McGill, Jack Marchant, Dennis Mitchell, Oregon Department of TransportationPortland State University Distance Learning Center for making the streaming easyMy colleagues Jennifer Dill, Chris Monsere and John GliebeSeminar enthusiasts and participantsRyan Gratzer
Travel time project teams, past and presentKristin Tufte, Sirisha Kothuri, David Lovell, Ben Zielke, Rafael Fernandez, Ed Anderson Sutti Tantiyanugulchai, Roger Lindgren, Monica LealGalen McGill, Jack Marchant, Dennis Mitchell, Oregon Department of TransportationPortland State University Distance Learning Center for making the streaming easyMy colleagues Jennifer Dill, Chris Monsere and John GliebeSeminar enthusiasts and participantsRyan Gratzer