1 presented at 2008 north american paramics user group meeting 1 evaluation of incorporating hybrid...

1

1Presented at 2008 North American Paramics User Group Meeting

Evaluation of Incorporating Hybrid Vehicle Use of HOV Lanes

Lianyu ChuCLR Analytics Inc

July 14, 2008 @ NA Paramics User Group Meeting

2


Background

• Many states have demonstrated the effectiveness of HOV lanes

• HOV lane operation is criticized – Underutilization of roadway capacity – Limited ability to shift solo drivers to transit and

carpools

• Conversion to other type of operation – Allowing single occupant hybrid vehicles (SOHV)– In southern California

• From buffer separate to continuous access

– HOT

3


HOV lanes

• What is HOV lane?• Northern CA

– Continuous access– Operated during peak periods– HOV 2+ or 3+

• Southern CA– Limited access– Operated 24 hours a day– HOV 2+

• HOV lanes in CA– About 30% of the total of US

4


Current Hybrid HOV policy in California

• Starting Jan 2005– Stickers will expire in 2010.

• Vehicle models > 45 miles per gallon – Toyota Prius– Hybrid Honda Civic – Honda Insight

• Maximum number of stickers– Originally, 75K,

• reached at Nov 2006

– Then, decided to offer 10K more• Reaches 85K on 2/2/2007

– No more stickers

5


Motivation

• Statewide policy– San Francisco Bay Area

• there is substantial reserve capacity on HOV lanes

– Orange County, • HOV lanes have almost reached their nominal capacity of

1,650 vehicles per hour, carrying an average of 1,568 vph in 1998

• Purpose:– Investigate impacts of the policy in OC

• Operational effects • Emission effects

6


Study Network

7


Socio-economic characteristics &

Hybrid Population Data

PolicyDesign scenario

Estimate hybrid demand

Select study site

Build micro-simulation model in

Paramics

Calibrate micro-simulation model

Run simulation for each scenario

Performance measures

Estimate SOV / HOV demand

Planning model

Compare simulation results

Policy Implications

Methodology

8


Model

• All major freeways– I-5, I-405, SR-55, SR-22,

SR-57, and SR-91– Most freeway mainline

have 4-6 lanes– Excluding 6-mile the

southern part of I-5, the section of SR-91 express lane.

• Model summary– 200 HOV lane miles – 800 mainline lane miles

• Total zones: 265• AM Peak hour model

9


HOV lane modeling

• Network construction (buffer-separated HOV) – The mixed-flow lanes and HOV lanes were coded as

two separate links wherever required. – Non-buffered sections were coded as a single link

between ingress and egress points.

• Route choice models– Combination of the use of three routing models

• All-or-nothing• Stochastic route choice• Dynamic feedback

10


Model calibrationCalibration data preparation

and data analysis

Initial calibration / setting of route choice models

OD demand estimation

Network performance calibration and validation

Final model

Route choice modification

11


Calibration data preparation

• Base year: 2005– Both flow and speed data were collected from PeMS

• Flow data:– Gather data from four different years (2002-2005) – Some on-ramp and off-ramp locations

• estimated based on Caltrans census dataset or mainline data

• Speed data– 5-min speed data were collected from freeways for 3

months – Draw the 50th percentile speed contour maps based

on Tuesday to Thursday’s data– Used to identify freeway bottlenecks.

12


Demand Estimation• Pattern OD matrix

– OCTAM: planning model of Orange County, CA– Extracted using MMA analysis in TransCAD

• Fine-tune OD matrix using Paramics OD estimator• HOV demand estimation

– A fixed percentage: 21.7%– Based on California DOT’s HOV report and loop detector data– Trial-and-error based on range from 14% to 25%

• Hybrid demand estimation model :– Estimate each zone’s hybrid percentage– Multinomial regression and binomial regression model

• Social-economic data• Survey data

13


HOV volume / total volume (based on 2005 D12 HOV report)

Peak period (6:30 - 9:00) Peak hour (6:30-7:30)

Name Freeway PMHOV

volumeTotal

volume PercentageHOV

volumeTotal

volume Percentage

Los Alisos Boulevard I5 NB 18 4365 31995 13.6% 1883 13122 14.3%

Tustin Ranch Road I5SB R28.3 5805 26021 22.3% 2741 10957 25.0%

Main St I5SB 33.1 4807 25021 19.2% 1995 10628 18.8%

Harbor Blvd I5SB 37.4 3754 20951 17.9% 1833 9099 20.1%

Broadway st I5SB 38.7 4304 21368 20.1% 1785 9183 19.4%

Von Karman I 405 NB 7.4 2887 28182 10.2% 1320 11625 11.4%

Ward St I 405 SB 13.2 3846 30094 12.8% 1598 12749 12.5%

Walnut Ave SR 55 SB 14.2 4492 19051 23.6% 1999 8607 23.2%

Warner Ave SR 55 SB R 8.5 5284 23665 22.3% 2345 10310 22.7%

Yorba Linda Blvd SR 57 SB 18.3 3729 16134 23.1% 1571 6785 23.2%

Harbor SR 91 WB 3.3 3377 18018 18.7% 1636 7818 20.9%

• HOV volume / total volume percentage:

– peak period: 10.2% - 23.1%– peak hour: 11.4% - 25%

• Patterns:– HOV lanes attract more carpoolers

since HOV lane is faster – Congested areas: higher percentages

14


Regression Model for Share of Hybrid Vehicles

Variable Coefficient t-statistic

Median Household Income /$10k 0.012364 11.25

Average Household Size 0.002286 1.46

Average Workers per Household 0.018347 2.96

Average Workers / Median Household Income -0.06142 -2.90

Constant 0.186429 26.72

Number of observations 62

R-squared 0.9866

Root MSE 0.00248

15


Model Calibration/Validations

Criteria and Measures FHWA targets Model Performance

Hourly flow: Model Vs Observed

GEH Statistic – Individual Link FlowsGEH < 5

> 85% of cases 70% of cases

Speed: Model Vs ObservedMatch bottleneck locations To analyst’s satisfaction Matched all major bottleneck

locations (see graphs)

Visual audits: Individual Link Speeds

Visually acceptable Speed-Flow relationship

BottlenecksVisually acceptable Queuing

To analyst’s satisfaction

To analyst’s satisfaction

Satisfied

Satisfied

Data for baseline model calibration- End of 2004 data from PeMS

16


5NB HOV Speed Contour: Observed

5NB HOV Speed Contour: Simulated

6:30

:30

6:40

:30

6:50

:30

7:00

:30

7:10

:30

7:20

:30

7:30

:30

864

1105

1305

1387

1652

200

222

2405

2508

2755

281

2979

309

319

350

3738

381

407

5-15 15-25 25-35 35-45 45-55 55-65 65-75

6:0

0

6:2

0

6:4

0

7:0

0

7:2

0

7:4

0

8:0

0

8:2

0

8:4

0

9:0

0

9:2

0

9:4

0

10:0

0

79.168(6.91)

80.898(8.64)

82.358(10.1)

83.628(11.37)

85.958(13.7)

87.608(15.35)

89.688(17.43)

91.078(18.82)

92.848(20.59)

94.458(22.2)

95.458(23.2)

96.758(R24.5)

98.058(R25.8)

100.351(28.1)

102.251(30)

102.851(30.6)

103.651(31.4)

104.501(32.25)

105.251(33)

105.851(33.6)

106.851(34.6)

107.851(35.6)

109.251(37)

110.251(38)

111.551(39.3)

112.751(40.5)

111.851(39.6)

112.951(40.7)

5-15 15-25 25-35 35-45 45-55 55-65 65-75

17


6:0

0

6:1

5

6:3

0

6:4

5

7:0

0

7:1

5

7:3

0

7:4

5

8:0

0

8:1

5

8:3

0

8:4

5

9:0

0

9:1

5

9:3

0

9:4

5

10

:0040.98

39.6

38.48

37.48

35.6

34.6

33.8

33.2

32.25

31.4

30.6

29.79

27.43

R25.8

R24.5

23.1

22.1

20.59

19.8

17.49

16.3

13.6

11.91

10.4

9.4

5-15 15-25 25-35 35-45 45-55 55-65 65-75

6:30

:30

6:40

:30

6:50

:30

7:00

:30

7:10

:30

7:20

:30

4098

405

393

390

380

3631

354

352

346

333

320

306

304

2835

277

2743

2666

2484

235

2305

2275

2059

2023

198

185

1726

163

1503

136

124

107

86

5-15 15-25 25-35 35-45 45-55 55-65 65-75

5SB HOV Speed Contour: Observed

5SB HOV Speed Contour: Simulated

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6:30

:30

6:35

:30

6:40

:30

6:45

:30

6:50

:30

6:55

:30

7:00

:30

7:05

:30

7:10

:30

7:15

:30

7:20

:30

7:25

:30

9

193

386

403

555

574

685

707

773

965

114

1285

1397

1482

1539

1676

1792

1924

5-15 15-25 25-35 35-45 45-55 55-65 65-75

6:0

0

6:1

5

6:3

0

6:4

5

7:0

0

7:1

5

7:3

0

7:4

5

8:0

0

8:1

5

8:3

0

8:4

5

9:0

0

9:1

5

9:3

0

9:4

5

10:0

00.7(0.93)

1.7(1.93)

3.08(3.31)

4.78(5.01)

5.51(5.74)

6.84(7.07)

8.17(8.4)

10.25(10.48)

11.37(11.6)

12.93(13.16)

14.31(14.54)

15.16(15.39)

16.53(16.76)

18.42(18.65)

20.1(20.33)

21.68(21.91)

23.39(23.62)

5-15 15-25 25-35 35-45 45-55 55-65 65-75



19


6:0

0

6:1

5

6:3

0

6:4

5

7:0

0

7:1

5

7:3

0

7:4

5

8:0

0

8:1

5

8:3

0

8:4

5

9:0

0

9:1

5

9:3

0

9:4

5

10:0

024.12

23.19

21.91

20.33

18.65

17.45

15.87

14.54

13.16

11.5

10.28

8.4

7.01

5.69

5.01

3.31

1.93

0.77

5-15 15-25 25-35 35-45 45-55 55-65 65-75

6:30

:30

6:40

:30

6:50

:30

7:00

:30

7:10

:30

7:20

:30

7:30

:30

2069

1798

166

1472

125

112

83

701

569

403

288

96

5-15 15-25 25-35 35-45 45-55 55-65 65-75



20


6:30

:30

6:35

:30

6:40

:30

6:45

:30

6:50

:30

6:55

:30

7:00

:30

7:05

:30

7:10

:30

7:15

:30

7:20

:30

7:25

:30

694

716

785

919

941

100

102

104

105

1174

139

1522

5-15 15-25 25-35 35-45 45-55 55-65 65-75



6:00

6:10

6:20

6:30

6:40

6:50

7:00

7:10

7:20

7:30

7:40

7:50

8:00

8:10

8:20

8:30

8:40

8:50

9:00

9:10

9:20

9:30

9:40

9:50

10:0

0R6.94

R7.85

R9.19

R10

10.4

10.84

11.74

12.7

13.9

14.6

15.4

16.2

5-15 15-25 25-35 35-45 45-55 55-65 65-75

21


6:3

0:3

0

6:3

5:3

0

6:4

0:3

0

6:4

5:3

0

6:5

0:3

0

6:5

5:3

0

7:0

0:3

0

7:0

5:3

0

7:1

0:3

0

7:1

5:3

0

7:2

0:3

0

7:2

5:3

0

1612

120

1162

1084

919

1351

812

762

703

688

5-15 15-25 25-35 35-45 45-55 55-65 65-75

6:00

6:15

6:30

6:45

7:00

7:15

7:30

7:45

8:00

8:15

8:30

8:45

9:00

9:15

9:30

9:45

10:0

016.2

14.4

13.2

10.84

R10

R7.62

5-15 15-25 25-35 35-45 45-55 55-65 65-75



22


6:30

:30

6:35

:30

6:40

:30

6:45

:30

6:50

:30

6:55

:30

7:00

:30

7:05

:30

7:10

:30

7:15

:30

7:20

:30

7:25

:30

2206

1994

1973

1837

1818

1741

1718

1646

1483

1465

1345

1327

124

1108

5-15 15-25 25-35 35-45 45-55 55-65 65-75

6:00

6:10

6:20

6:30

6:40

6:50

7:00

7:10

7:20

7:30

7:40

7:50

8:00

8:10

8:20

8:30

8:40

8:50

9:00

9:10

9:20

9:30

9:40

9:50

10:00

22.06

19.73

18.85

18.18

17.18

16.11

14.83

14.4

13.45

12.58

11.55

11.08

5-15 15-25 25-35 35-45 45-55 55-65 65-75



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Scenario Construction• Base Case:

– No Hybrids allowed on HOV lanes

– before California’s bill AB 2628 passed

• Scenario 1:– 36K Hybrids in CA (Nov 2005)– 3707 of 36K hybrids in OC

• Scenario 2:– 50K Hybrids (April 2006)– 5216 of 50K hybrids in OC

• Scenario 3:– 75K Hybrids (Nov 2006)

• Scenario 4:– 100K Hybrid (near future)

Scenarios SOV HOV Hybrid

Base Case 78.3 21.7 0.00

scenario 1 76.8 21.7 1.6

Scenario 2 76.2 21.7 2.2

Scenario 3 75.1 21.7 3.2

Scenario 4 74.0 21.7 4.3

* Total trips for study network: 238K

DMV data show:

-About 10% of CA hybrids are in OC

24


Performance Measures

• Overall network performance measures: – Vehicle Hours Traveled (VHT)– Vehicle Miles Traveled (VMT)

• Corridor performance measures:– Average corridor speed– Speed

• SAFETEA-LU needs HOV lanes to keep speed higher than 45 mph for 90% of the peak periods

– LOS• Caltrans has the authority to remove “individual HOV lanes

or portions of those lanes,” if traffic condition exceeds LOS C.

• Emissions & Fuel consumptions– Comprehensive Modal Emission Model (CMEM) from UC

Riverside– second-by-second emissions

25


HOV Segments for further analysis

Freeways DirectionsDistance(miles)

ML sections

HOVsections

I-405NB 22 4 5

SB 22 4 4

I-5NB 34 7 7

SB 34 6 7

SR-55NB 15 4 3

SB 15 3 3

SR-57NB 11 3 3

SB 11 3 4

SR-91EB 8 3 4

WB 8 3 3

-Total 43 HOV sections

-Study period: 5minutes (for 1-hour data)

26


Simulation design

• Assuming no HOV lane violations during simulation. • Simulations period

– One peak hour in AM – Simulate for 1 hour and 30 minutes. – The first 30 minutes of simulation: warm-up period

• MOE– Collected using different plug-ins – Only the last one hour of the simulations were analyzed.

• Base scenario– used as reference to evaluate other scenarios.

• Five runs were conducted per scenario– The results from the median run are used for analysis.

27


-2

-1.5

-1

-0.5

0

0.5

1

1.5

SC1 SC2 SC3 SC4

Per

cen

tag

e o

f in

crea

se

VMT VHT

VMT BC SC1 SC2 SC3 SC4

BC 0

SC1 0.3 0

SC2 0.5 0.4 0

SC3 0.75 0.6 0.65 0

SC4 0.98 0.9 0.9 0.75 0

Overall Network Performance

VHT BC SC1 SC2 SC3 SC4

BC 0

SC1 0.9 0

SC2 0.975 0.85 0

SC3 0.98 0.9 0.7 0

SC4 0.99 0.95 0.8 0.4 0

Confidence interval for the comparison

28


Comparison of HOV & ML (I-5 & I-405)

0

10

20

30

40

50

60

70

BaseCase

Scenario1

Scenario2

Scenario3

Scenario4

Sp

ee

d (

mp

h)

I-405 NB HOV I-405 NB ML

0

10

20

30

40

50

60

BaseCase

Scenario1

Scenario2

Scenario3

Scenario4

Spe

ed (

mph

)

I-405 SB HOV I-405 SB ML

0

10

20

30

40

50

60

Base Case Scenario 1 Scenario 2 Scenario 3 Scenario 4

Sp

ee

d (

mp

h)

I-5 NB HOV I-5 NB ML

0

10

20

30

40

50

60


Sp

ee

d (

mp

h)

I-5 SB HOV I-5 SB ML

29


Comparison of HOV & ML (SR-55&57)

0

10

20

30

40

50

60

70

80


Sp

ee

d (

mp

h)

SR-55 NB HOV

SR-55 NB ML

0

10

20

30

40

50

60


Sp

ee

d (

mp

h)

SR-55 SB HOV SR-55 SB ML

0

10

20

30

40

50

60

70


Sp

ee

d (

mp

h)

SR-57 NB HOV SR-57 NB ML

0

10

20

30

40

50

60


Sp

ee

d (

mp

h)

SR-57 SB HOV SR-57 SB ML

30


Speed Distribution: HOV sections

0

10

20

30

40

50

60

70


Pe

rce

nta

ge

Spd<15 Spd<25 Spd<35 Spd<45 Spd<55 Spd>55

• With more traffic allowed into HOV lanes, HOV lane performance degrades

31


Percentage of Sections & Time periods with speed greater than 45 mph

77

75

72

69

66

60 65 70 75 80

Base Case

Scenario 1

Scenario 2

Scenario 3

Scenario 4

Percentage

32


LOS Distribution: HOV lanes

0

5

10

15

20

25

30

35

40


Pe

rce

nta

ge

LOS A LOS B LOS C LOS D LOS E LOS F

33


Percentage of Sections & Time spent less than 26 veh/mile/lane (LOS C)

81

70

66

60

55

0 20 40 60 80 100

Base Case

Scenario 1

Scenario 2

Scenario 3

Scenario 4

34


Comparison of Emissions

-6.00

-5.00

-4.00

-3.00

-2.00

-1.00

0.00

Scenario 1 Scenario 2 Scenario 3 Scenario 4

CO2 CO HC NOx Fuel

• Scenario 4 reduces emissions significantly– due to high share of Hybrids

35


Policy decision: multi-objective optimization problem

• Maximize the benefits obtained from emission – SC4 is the best

• Meet FHWA’s SAFETEA-LU’s requirement.– Base-year: doesn’t meet– Practical: allow another 10% HOV lanes to be under 45 mph – SC1-3 can meet

• HOV lanes must continue to provide benefits for existing carpoolers. – MOE: percentage of ave. speed difference between HOV &

mixed-flow lanes – Speed difference in Sc1-SC3 are 21%, 16% and 11%. – An intuitive feeling : at least 15% speed difference

• SC1-2 meet

• Scenario 2 appears likely to satisfy the desires of all stakeholders.

36


Findings

• With the increase of Hybrids, the operational performance of HOV lanes degrades

• Overall, Scenario 2 performs more effectively (50K hybrid)– HOV lane speed is reduced by less than 5% in scenario 2

• From air quality perspective, scenario 4 (100K hybrids) outperforms.

• Hybrid HOV policy may have impacted sales of Hybrid vehicles– April 2006: 50K– Nov 2006: 75K– Feb 2, 2007: 85K

37


Policy Implication

• The policy is successful in reducing emission by allowing hybrid vehicles using HOV lanes.

• The policy is not appropriate to be applied to the HOV lanes that don’t have reserved capacity.

• 50K hybrid vehicle permits (SC2) throughout the state could be the maximum that the Orange County HOV system can take without much degradation.

• The policy could have been implemented more strategically, i.e. applying to selected freeways and/or selected time periods.

38


Project team

CCIT, UC BerkeleyLianyu Chu

UC IrvineWill Recker

David BrownstoneTom Golob

K S NesamaniChris Breiland

Western Michigan UniversityJun Seok Oh

39


Thank you!

Questions & Comments

1 presented at 2008 north american paramics user group meeting 1 evaluation of incorporating hybrid...

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