Overview and Results of a Statewide Survey of Vehicle ... · PDF fileOverview and Results of a Statewide Survey of Vehicle ... CA 92521-0434. ... Cruz Inyo Santa Clara Fresno Merced

Center for Environmental Research and Technology

University of California, RiversideBourns College of Engineering

California Air Resources BoardChairman’s Air Pollution Seminar Series

June 12, 2002

Overview and Results of a Statewide Survey of Vehicle Registration Status in California

Theodore Younglove, Tom Durbin, Carrie Malcolm, and Matt Smith

Bourns College of EngineeringCenter for Environmental Research and Technology University of California Riverside, CA 92521-0434



Project Sponsors:

California Air Resources Board

South Coast Air Quality Management District



Acknowledgments:California Air Resources Board

Alberto Ayala, Mark Carlock, Sandee Kidd

Department of Consumer Affairs, Bureau of Automotive Repair

David Amlin, Mark Duewel, Kathy Runkle, and Greg Sweet

Data Collection

Hugo Galdamez, John Gaskins, Shayna Golbaf, Beth Lee, Don Pacocha,

Alison Rowlen, Judy Swineford, and Sylvester Wheeler

Data Entry

Jennifer Anderson, Warren Katzenstein, Lindsey Miller, Shelly Miller,

Andrea Ruiz, Jessica Walters, and Ryan Wicks



Site Selection

• Data collected in all 58 counties in California, proportional to

county population.

• Minimum county sample size set to 200. Actual sampling was less

in the smallest population counties.



Site Selection

• Data collected at randomly selected zip codes within each county.

• Sample size proportional to zip code population.

• Random parking lots throughout the zip code.



Parking Lot Selection



Data Capture

• Data collected by cruising parking lots and photographing vehicles in the lot.

• Data collected at 3 to 5 mph without stopping.



Data Capture

• Unregistered Vehicle Survey data collection using digital still

cameras.

– Toshiba M4 digital camera selected for rapid refresh rate (0.8

seconds between pictures).

• Data stored on Flash Media for download to PC for data entry.



Data Capture



Data Capture



Data Capture



Data Capture



Data Capture: ZIP Code Centroids

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Siskiyou

DelNorte

Modoc

Humboldt

Trinity ShastaLassen

TehamaPlumas

ButteMendocinoGlenn Sierra

YubaLake

NevadaColusa

PlacerSutter

El DoradoYolo

AlpineNapaSonoma

Sacramento

Mono

Amador

CalaverasTuolumne

MarinSan

Joaquin

Solano

ContraCosta

StanislausAlameda

Mariposa

San Francisco

Madera

SanMateo

Merced

Fresno

SantaClara

Inyo

SantaCruz

SanBenito

Monterey Tulare

Kings

Kern

San Bernardino

San LuisObispo

Ventura

Riverside

SantaBarbara

Orange

San Diego

LosAngeles

Imperial



License Plate Obstructions - Non-Random



License Plate Obstructions - Random



Public Interactions

95% Oblivious 4.9% Notice, but don’t care

0.1% Notice, but not happy



Data Analysis

• Two methods of registration classification:

– Observed data.

–Vehicle license plates were characterized by registered,

unregistered, dealer, front, no plate, out of state, unknown

state, and unknown based on stickers observed on the plate.

– DMV comparisons.

–Vehicle license plate data will be submitted to the DMV to

obtain official registration status.



Data Analysis



Average County Non-Registration Rate 3.5%

Siskiyou

DelNorte

Modoc

Humboldt


TehamaPlumas


YubaLake

NevadaColusa

PlacerSutter

El DoradoYolo

AlpineNapaSonoma

Sacramento

Mono

Amador

CalaverasTuolumne

MarinSan

Joaquin

Solano

ContraCosta

StanislausAlameda

Mariposa

San Francisco

Madera

SanMateo

Merced

Fresno

SantaClara

Inyo

SantaCruz

SanBenito

Monterey Tulare

Kings

Kern

San Bernardino

San LuisObispo

Ventura

Riverside

SantaBarbara

Orange

San Diego

LosAngeles

Imperial

Siskiyou

DelNorte

Modoc

Humboldt


TehamaPlumas


YubaLake

NevadaColusa

PlacerSutter

El DoradoYolo

AlpineNapaSonoma

Sacramento

Mono

Amador

CalaverasTuolumne

MarinSan

Joaquin

Solano

ContraCosta

StanislausAlameda

Mariposa

San Francisco

Madera

SanMateo

Merced

Fresno

SantaClara

Inyo

SantaCruz

SanBenito

Monterey Tulare

Kings

Kern

San Bernardino

San LuisObispo

Ventura

Riverside

SantaBarbara

Orange

San Diego

LosAngeles

Imperial

Percent Unregistered Vehicles0 - 1 1 - 22 - 33 - 44 - 55 - 66 - 7



County Non-Registration Rate: All counties

0

5

10

15

20

0-1 1-2 2-3 3-4 4-5 5-6 >6

Percent Unregistered Vehicles

Num

ber o

fC

ount

ies



County Non-Registration Rate: Counties with population >300,000

02

4

68

10

0-1 1-2 2-3 3-4 4-5 >5

Percent Unregistered Vehicles

Num

ber

ofC

ount

ies



Non-Registration Rate by length of time unregistered (overall 3.38%)–Instantaneous - <3 months–Long Term - 3 months to 2 years–Chronic - > 2 years

0.95

2.41

0.030.0 0.5 1.0 1.5 2.0 2.5 3.0

Instanteous Long Term Chronic

Unregistration Status

Percent of Total



Results:Riverside County: Percent unregistered vehicles by zip code



Results:Riverside County: Percent of vehicles > 3 months unregistered

0

5

10

15

1979

1984

1986

1989

1991

1994

1996

1998

Model Year

Perc

ent



Results:Riverside County: Number of vehicles > 3 months unregistered

0

2

4

6

8

1979

1984

1986

1989

1991

1994

1996

1998

Model Year

Num

ber

of V

ehicl

es



Results:Demographic Analysis: County Median Household Income

2 29.383 14.692 9.157 .000455 88.246 1.60457 117.629

DF Sum of Squares Mean Square F-Value P-ValueRegressionResidualTotal

ANOVA Table% Unreg vs. Median HI ($)

-9.308 3.036 -9.308 -3.066 .0034.001 1.879E-4 3.668 3.744 .0004

-9.640E-9 2.778E-9 -3.400 -3.470 .0010

Coefficient Std. Error Std. Coeff. t-Value P-ValueInterceptMedian HI ($)Median HI ($)^2

Regression Coefficients% Unreg vs. Median HI ($)

-1

0

1

2

3

4

5

6

7

% U

nreg

15000 20000 25000 30000 35000 40000 45000 50000Median HI ($)

Y = -9.308 + .001 * X - 9.64E-9 * X^2; R^2 = .25

Regression Plot



Results:Demographic Analysis: County Population

1 5.722 5.722 2.864 .096256 111.907 1.99857 117.629


ANOVA Table% Unreg vs. population

2.517 .202 2.517 12.431 <.00012.344E-7 1.385E-7 .221 1.692 .0962

Coefficient Std. Error Std. Coeff. t-Value P-ValueInterceptpopulation

Regression Coefficients% Unreg vs. population

-1

0

1

2

3

4

5

6

7

% U

nreg

-1000000 1000000 3000000 5000000 7000000 9000000population

Y = 2.517 + 2.344E-7 * X; R^2 = .049

Regression Plot



Results:Demographic Analysis: County Percent Home Ownership

1 2.482 2.482 1.207 .276656 115.147 2.05657 117.629


ANOVA Table% Unreg vs. Owner %

4.436 1.633 4.436 2.716 .0088-.028 .026 -.145 -1.099 .2766

Coefficient Std. Error Std. Coeff. t-Value P-ValueInterceptOw ner %

Regression Coefficients% Unreg vs. Owner %

-1

0

1

2

3

4

5

6

7

% U

nreg

30 35 40 45 50 55 60 65 70 75 80Ow ner %

Y = 4.436 - .028 * X; R^2 = .021

Regression Plot



Siskiyou

DelNorte

Modoc

Humboldt


TehamaPlumas


YubaLake

NevadaColusa

PlacerSutter

El DoradoYolo

AlpineNapaSonoma

Sacramento

Mono

Amador

CalaverasTuolumne

MarinSan

Joaquin

Solano

ContraCosta

StanislausAlameda

Mariposa

San Francisco

Madera

SanMateo

Merced

Fresno

SantaClara

Inyo

SantaCruz

SanBenito

Monterey Tulare

Kings

Kern

San Bernardino

San LuisObispo

Ventura

Riverside

SantaBarbara

Orange

San Diego

LosAngeles

Imperial

Percent Out of State Vehicles0 - 12 - 55 - 1010 - 1515 - 20>20

Out of State Vehicles



Percentage of missed vehicles

Imperial

LosAngeles

San Diego

Orange

SantaBarbara

Riverside

Ventura

San LuisObispo

San Bernardino

Kern

Kings

TulareMonterey

SanBenito

SantaCruz

Inyo

SantaClara

Fresno

Merced

SanMateo

Madera

San Francisco

MariposaAlameda

Stanislaus

ContraCosta

Solano

SanJoaquin

MarinTuolumne

Calaveras

Amador

Mono

Sacramento

Sonoma Napa Alpine

Yolo El DoradoSutter

PlacerColusa

NevadaLake

Yuba

SierraGlennMendocino Butte

PlumasTehama

LassenShastaTrinity

Humboldt

Modoc

DelNorte

Siskiyou

Percent Missed Vehicles0 - 22 - 55 - 1010 - 2020 - 4040 - 65



Results:Riverside County: Fleet composition

0

100

200

300

400

1972

1975

1978

1981

1984

1987

1990

1993

1996

1999

Model Year

Num

ber

of V

ehicl

es



Results:Riverside County: Emission controls

TWC EGR Both Neither Unknown TotalRegistered 342 80 1803 18 22 2265

Unregistered 14 5 93 1 3 116

020406080

100

% TWC % EGR % Both % None

Emission Control

Perc

ent o

f Fle

et

Registered

Unregistered



Results:Fleet Composition: DMV, On-Road, and Parking Lot

L o s A n g e l e s C o u n t y

0

2 0

4 0

6 0

8 0

1 0 0

M o d e l Y e a r

Perc

ent D M V

SE L E V

U n r e g

O r a n g e C o u n t y

0

2 0

4 0

6 0

8 0

1 0 0

M o de l Y e a r

Perc

ent D M V

SE L E V

U n re g



Results:Smog Check Analysis; 64,892 license plates having Smog Check and observed registration status.

Field Number Pass Failed Gross Polluter Tampered Aborted UnknownStatus # % # % # % # % # % # %

Registered 51974 50423 97 682 1.3 250 0.48 25 0.1 391 0.8 203 0.4Instantaneous 1449 1385 95.6 30 2.1 13 0.90 2 0.1 12 0.8 7 0.5Long Term 601 549 91.4 18 3 19 3.16 2 0.3 10 1.7 3 0.50

Chronic 13 11 84.6 1 7.7 1 7.69 0 0.00 0 0.00 0 0.00Front 4921 4716 95.8 91 1.9 44 0.89 4 0.1 44 0.9 22 0.5

Unknown 7387 7015 95 157 2.1 66 0.89 13 0.2 83 1.1 53 0.7Total 66346 64100 979 393 46 540 288



Results:Travel Study: Origins and destination locations by zip code for 92505



Results:Travel Study Example: Geocoded destination locations for all of Riverside County

Total Addresses 98Matched Addresses 45Unmatched Total 53

Incomplete Addresses 16



Results:Travel Study: Average miles traveled in Riverside County by model year

02468

1012

1972

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

Model Year

Ave

rage

Mile

s



Results:Travel Study: Average miles traveled in Riverside County by business type

02468

10

Ban

k

Bus

ines

s

Educ

atio

n

Food

Gro

cery

Mal

l

Med

ical

Min

i Mal

l

Rec

reat

iona

l

Ret

ail

Ave

rage

Mile

s



Conclusions:• Unregistered vehicles typically older that the general vehicle population.

• Higher proportions of out of state vehicles on the road in:– Counties near the state border.– Zip codes and counties with tourist attractions.



Future Work:• Comparison of observed registration to DMV registration.

• Comparison of Smog Check results for registered and unregistered vehicles.

• In-depth travel study:– Geocode in ArcView all origins (home address of registered vehicle) and destinations (address of data collection sites).– Determine distance traveled by model year, business type and characterize cross county travel.



Samples of Captured Vehicles



California - Summer 2000

Overview and Results of a Statewide Survey of Vehicle ... · PDF fileOverview and Results of a Statewide Survey of Vehicle ... CA 92521-0434. ... Cruz Inyo Santa Clara Fresno Merced

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