Analysis of NBI Data for California Bridges

Rosa Vasconez, Emily Yu

California State Polytechnic University, Pomona

July 2016

University of California Center on Economic Competitiveness in Transportation

What is the NBI?

National Bridge Inventory (NBI) • A database compiled by the Federal Highway Administration

(FHWA)

• Used to analyzed the conditions of all the bridges and tunnels in the United States

Research Objective

Understand the National Bridge Inventory and its resources and limitations

Retrieve relevant data to the bridge population in California

Analyze data to get information on bridge performance and properties

Methodology

• Analyze data from the National Bridge Inventory and the National Bridges website • NBI information taken from “Frequently Requested Charts”

‐ Information deciphered from ASCII files

• National Bridges website: database that extracts information from the NBI ASCII file

‐ Provides informative data about specific counties

Research Parameters

• Material Composition • Wearing Surface and Deck Protection • Age • Functional System • Structural Status • Average Daily Traffic (ADT) • Ownership • Federal aid and Non-federal aid bridge distribution

Results

Information on the performance of the bridge population of California in terms of strength and serviceability

Correlation of bridge performance with geographic location, material type, traffic volume and age

0

2

4

6

8

10

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14

AK AL

AR

AZ

CA

CO CT

DC

DE FL GA HI

IA ID IL IN KS

KY

LA

MA

MD

ME MI

MN

MO

MS

MT

NC

ND

NE

NE

NH NJ

NM NY

OH

OK

OR PA RI

SC SD TN

TX

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VT

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WI

WV

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Perc

enta

ge o

f Tot

al B

ridg

e C

ount

(%)

State

United States Bridge Distribution Represented by Percentage of Total Bridge Count

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2

4

6

8

10

12

14

AK AL

AR

AZ

CA

CO CT

DC

DE FL GA HI

IA ID IL IN KS

KY

LA

MA

MD

ME MI

MN

MO

MS

MT

NC

ND

NE

NE

NH NJ

NM NY

OH

OK

OR PA RI

SC SD TN

TX

UT

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VT

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Perc

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f Tot

al B

ridg

e Are

a (%

)

State

United States Bridge Distribution Represented by Percentage of Total Bridge Area

Southern California Counties

• 25, 406 bridges in California • 38% are in Southern California

3% 14%

5%

4%

5%

6% 2%

61%

Distribution of California Bridges (Bridge Count)

Kern

Los Angeles

Orange

Riverside

San Bernardino

San Diego

Ventura

All Other Counties inCalifornia

Material Composition

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

AK AL

AR

AZ

CA

CO CT

DC

DE FL GA HI

IA ID IL IN KS

KY

LA

MA

MD

ME MI

MN

MO

MS

MT

NC

ND

NE

NE

NH NJ

NM NY

OH

OK

OR PA RI

SC SD TN

TX

UT

VA

VT

WA

WI

WV

WY PR

Cou

nt o

f Bri

dges

(104 )

State

Material Composition of United States Bridges Represented by Bridge Count

ConcreteSteelOther

66%

30%

4%

Material Composition of United States Bridges

ConcreteSteelOther

86%

11% 3%

Material Composition of California Bridges

ConcreteSteelOther

0

500

1000

1500

2000

2500

3000

Kern Los Angeles Orange Riverside SanBernardino

San Diego Ventura

Num

ber

of B

ridg

es

County

Material Composition of Southern California County Bridges

ConcreteSteelOther

Wearing Surface and Deck Protection

Provide protection from environmental and external factors

0

2

4

6

8

10

12A

LA

K AZ

AK

CA

CO CT

DC

DE FL GA HI

IA ID IL IN KS

KY

LA

MA

MD

ME MI

MN

MO

MS

MT

NC

ND

NV

NE

NH NJ

NM NY

OH

OK

OR PA RI

SC SD TN

TX

UT

VA

VT

WA

WI

WV

WY PR

Perc

enta

ge o

f Cou

nt (%

)

State

Wearing Surfaces of United States Bridges Represented in Percentage of Total Count

88%

12%

United States Bridges with Wearing Surfaces

Wearing Surface

None

58%

42%

California Bridges with Wearing Surfaces

Wearing Surface

None

0

5

10

15

20

25

30A

LA

K AZ

AK

CA

CO CT

DC

DE FL GA HI

IA ID IL IN KS

KY

LA

MA

MD

ME MI

MN

MO

MS

MT

NC

ND

NV

NE

NH NJ

NM NY

OH

OK

OR PA RI

SC SD TN

TX

UT

VA

VT

WA

WI

WV

WY PR

Perc

enta

ge o

f Cou

nt (%

)

State

Deck Protection of United States Bridges Represented in Percentage of Total Bridge Count

32%

68%

United States Bridges with Deck Protection

Deck Protection

None

2%

98%

California Bridges with Deck Protection

Deck Protection

None

Age Life expectancy of bridges is 70 years old.

However, accounting for external and environmental factors, life expectancy is 50 years old.

0

5

10

15

20

25Pe

rcen

tage

of C

ount

(%)

Year Built

Age of California Bridges Represented by Percentage of Bridge Count

0

5

10

15

20

25Pe

rcen

tage

of C

ount

(%)

Year Built

Age of Steel California Bridges Represented by Percentage of Bridge Count

0

5

10

15

20

25Pe

rcen

tage

of C

ount

(%)

Year Built

Age of Concrete California Bridges Represented by Percentage of Bridge Count

Functional System

42%

16%

19%

23%

Functional Systems of California Bridges

Principle Arterial

Minor Arterial

Collector

Local

Structural Status

Functionally Obsolete: • The design of the bridge is no longer

functionally adequate for its task • Does not accommodate traffic flow or

vertical clearance is restrictive • Does not meet safety regulations

Structurally Deficient: • The bridge is in need of maintenance • There are flaws in the structure and the

bridge needs repair • Minor concrete cracks in bridge

10%

17%

73%

Structural Status of California Bridges

StructurallyDeficient Bridges

FunctionallyObsolete Bridges

Bridges withoutdeficiency

1% 13%

2% 4%

4% 2% 2%

72%

Structurally Deficient Bridges in Southern California

Kern

Los Angeles

Orange

Riverside

San Bernardino

San Diego

Ventura

Structurally DeficientBridges in other Counties

1%

21%

6%

3% 2%

4% 2%

61%

Functionally Obsolete Bridges in California

Kern

Los Angeles

Orange

Riverside

San Bernardino

San Diego

Ventura

Functionally ObsoleteBridges other Counties

- 100 200 300 400 500 600 700 800 900

1,000

Cou

nt o

f Bri

dges

County

Southern California Structurally Deficient and Functionally Obsolete Bridges Represented by Count of Bridges

Structurally DeficientBridges

FunctionallyObsolete Bridges

0

50

100

150

200

250

300

350C

ount

of B

ridg

es

County

Structurally Deficient Steel and Concrete Bridges

ConcreteSteel

0100200300400500600700800900

Cou

nt o

f Bri

dges

County

Functionally Obsolete Steel and Concrete Bridges

ConcreteSteel

Average Daily Traffic on Bridges Total traffic averaged over 365 days.

0

1

2

3

4

5

6

7A

LA

K AR

AZ

CA

CO CT

DC

DE FL GA HI

IA ID IL IN KS

KY

LA

MA

MD

ME

MI

MN

MO

MS

MT

NC

ND

NE

NE

NH NJ

NM NY

OH

OK

OR PA RI

SC SD TN

TX

UT

VA

VT

WA

WI

WV

WY

Aver

age

Num

ber

of C

ars (

108 )

State

Total Average Daily Traffic on Bridges

Ownership

49%

29%

18%

4%

Ownership of California Bridges Represented by Percentage of Bridge Count

State

County

City

Other

77%

8%

13% 2%

Ownership of California Bridges Represented by Percentage of Area

State

County

City

Other

Federally and Non-Federally Aided Bridges

0

0.5

1

1.5

2

2.5

3

3.5

4

AK AL

AR

AZ

CA

CO CT

DC

DE FL GA HI

IA ID IL IN KS

KY

LA

MA

MD

ME MI

MN

MO

MS

MT

NC

ND

NE

NE

NH NJ

NM NY

OH

OK

OR PA RI

SC SD TN

TX

UT

VA

VT

WA

WI

WV

WY PR

Cou

nt o

f Bri

dges

(104 )

State

Federally and Non-Federally Aided united States Bridges Represented in Count

FederallyAidedHighwayBridge

Non-FederallyAidedHighwayBridge

Conclusion

• Trends found in Research (bridge count and bridge area): • Geographic distribution and bridge attributes

• Bridge condition and bridge attributes

• Majority of the information on bridges in the United States are not deciphered in ASCII files

• HTML and Excel Format

• NBI information limited to the tables provided on the FHWA website

Questions?

88%

12%

United States Bridges with Wearing Surfaces

Wearing Surface

None

58%

42%

California Bridges with Wearing Surfaces

Wearing Surface

None

38%

57%

5%

Wearing Surfaces of California Bridges

Monolithic Concrete,Integral Concrete, LatexConcrete, Low SlumpConcrete

Bituminous

Epoxy Overlay, Wood orTimber, Gravel, Other

32%

68%

United States Bridges with Deck Protection

Deck Protection

None

2%

98%

California Bridges with Deck Protection

Deck Protection

None56%

13%

2%

22%

7%

Deck Protection of California Bridges

Epoxy Coated Reinforcing

Polymer Impregnated

Galvanized Reinforcing,Cathodic Protection,Internally Sealed, OtherCoated ReinforcingUnknown

Bridges on Main Freeways in California

US 101

I-10

I-405

I-210

I-5

0

200

400

600

800

1000

1200

1400

1600

1800

I-210 I-10 US 101 I-5 I-405

Cou

nt o

f Bri

dges

Freeway

Number of California Bridges in Each Freeway

0

20

40

60

80

100

120

140

160

180

I-210 I-10 US 101 I-5 I-405

Cou

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f Bri

dges

Freeway

California Bridges and the Number of Structurally Deficient/Functionally Obsolete Bridges on the Freeways

Structurally DeficientFunctionally Obsolete

0

20

40

60

80

100

120

140

160

I-210 I-10 US 101 I-5 I-405

Cou

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f Bri

dges

Freeway

Structurally Deficient and Functionally Obsolete Major Freeway and Interstate Bridges in Califonia Represented by Count of Bridges

Structurally Deficient ConcreteStructurally Deficient SteelFunctionally Obsolete ConcreteFunctionally Obsolete Steel

0

50

100

150

200

250

300

350

400

Kern LosAngeles

Orange Riverside SanBernardino

San Diego Ventura

Cou

nt o

f Bri

dges

County

Southern California Interstate and Freeway Bridges

I-210I-10US 101I-5I-405