Analysis of NBI Data for

California Bridges

Emily YuCalifornia State Polytechnic University,

Pomona

Advisor: Dr. Rosa Vasconez, PE, LEED AP

Wednesday, August 19, 2015

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

• Take data from the National Bridge Inventory and the National Bridges website and create visual representations using Excel• 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

Anticipated 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

Results

AK AR CA CT DE GA IA IL KS LA MD M

IM

O MT ND NE NJ

NY OK PA SC TN UT VT WI

WY

0

2

4

6

8

10

12

14

United States Bridge Distribution Represented by Percentage of Total Bridge Count

State

Perc

enta

ge o

f Tot

al B

ridg

e C

ount

(%)

AK AR CA CT DE GA IA IL KS LA MD M

IM

O MT ND NE NJ

NY OK PA SC TN UT VT WI

WY

0

2

4

6

8

10

12

14

United States Bridge Distribution Represented by Percentage of Total Bridge Area

State

Perc

enta

ge o

f Tot

al B

ridg

e A

rea

(%)

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 in Cali-fornia

Material Composition

AK AR CA CT DE GA IA IL KS LA MD M

IM

O MT ND NE NJ

NY OK PA SC TN UT VT WI

WY

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

Material Composition of United States Bridges Represented by Bridge Count

ConcreteSteelOther

State

Cou

nt o

f Bri

dges

(104

)

66%

30%

4%

Material Composition of United States Bridges

ConcreteSteelOther

86%

11%3%

Material Composition of California Bridges

ConcreteSteelOther

Kern

Los Ange

les

Orange

Riversi

de

San Bern

ardino

San D

iego

Ventura

0

500

1000

1500

2000

2500

3000

Material Composition of Southern California County Bridges

ConcreteSteelOther

County

Num

ber

of B

ridg

es

Wearing Surface and Deck Protection

Provide protection from environmental and external factors

AL AZ CA CT DE GA IA IL KS LA MD M

IM

O MT ND NE NJ

NY OK PA SC TN UT VT WI

WY

0

2

4

6

8

10

12

Wearing Surfaces of United States Bridges Represented in Per-centage of Total Count

State

Perc

enta

ge o

f Cou

nt (%

)

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, In-tegral Concrete, Latex Concrete, Low Slump Concrete

Bituminous

Epoxy Overlay, Wood or Timber, Gravel, Other

AL AZ CA CT DE GA IA IL KS LA MD M

IM

O MT ND NE NJ

NY OK PA SC TN UT VT WI

WY

0

5

10

15

20

25

30

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

State

Perc

enta

ge o

f Cou

nt (%

)

32%

68%

United States Bridges with Deck Protection

Deck Protection

None

2%

98%

California Bridges with Deck Protection

Deck Protection

None

56%

12%

2%

22%

7%

Deck Protection of California Bridges

Epoxy Coated Reinforcing

Polymer Impregnated

Galvanized Reinforcing, Cathodic Protection, In-ternally Sealed, Other Coated Reinforcing

Unknown

Other

AgeLife expectancy of bridges is 70 years old.

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

old.

1908

and ea

rlier

1909

-1913

1914

-1918

1919

-1923

1924

-1928

1929

-1933

1934

-1938

1939

-1943

1944

-1948

1949

-1953

1954

-1958

1959

-1963

1964

-1968

1969

-1973

1974

-1978

1979

-1983

1984

-1988

1989

-1993

1994

-1998

1999

-2003

2004

-2008

2009

-2013

0

5

10

15

20

25

Age of California Bridges Represented by Percentage of Bridge Count

Year Built

Perc

enta

ge o

f Cou

nt (%

)

1908

and ea

rlier

1909

-1913

1914

-1918

1919

-1923

1924

-1928

1929

-1933

1934

-1938

1939

-1943

1944

-1948

1949

-1953

1954

-1958

1959

-1963

1964

-1968

1969

-1973

1974

-1978

1979

-1983

1984

-1988

1989

-1993

1994

-1998

1999

-2003

2004

-2008

2009

-2013

0

5

10

15

20

25

Age of Steel California Bridges Represented by Percentage of Bridge Count

Year Built

Perc

enta

ge o

f Cou

nt (%

)

1908

and ea

rlier

1909

-1913

1914

-1918

1919

-1923

1924

-1928

1929

-1933

1934

-1938

1939

-1943

1944

-1948

1949

-1953

1954

-1958

1959

-1963

1964

-1968

1969

-1973

1974

-1978

1979

-1983

1984

-1988

1989

-1993

1994

-1998

1999

-2003

2004

-2008

2009

-2013

0

5

10

15

20

25

Age of Concrete California Bridges Represented by Percentage of Bridge Count

Year Built

Perc

enta

ge o

f Cou

nt (%

)

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

Structurally De-ficient Bridges

Functionally Obso-lete Bridges

Bridges without de-ficiency

2%13%

2%4%

4%

2%2%

72%

Structurally Deficient Bridges in Southern Cali-fornia

Kern

Los Angeles

Orange

Riverside

San Bernardino

San Diego

Ventura

Structurally Deficient Bridges in other Counties

1%

21%

6%

3%2%

5%2%

61%

Functionally Obsolete Bridges in California

Kern

Los Angeles

Orange

Riverside

San Bernardino

San Diego

Ventura

Functionally Obsolete Bridges other Counties

-

200

400

600

800

1,000

Southern California Structurally Deficient and Functionally Obso-lete Bridges Represented by Count of Bridges

Structurally Deficient Bridges

Functionally Obso-lete Bridges

County

Cou

nt o

f Bri

dges

050

100150200250300350

Structurally Deficient Steel and Concrete Bridges

ConcreteSteel

County

Cou

nt o

f Bri

dges

0100200300400500600700800900

Functionally Obsolete Steel and Concrete Bridges

ConcreteSteel

County

Cou

nt o

f Bri

dges

Average Daily Traffic on Bridges

Total traffic averaged over 365 days.

AL AR CA CT DE GA IA IL KS LAM

D MI

MO M

T ND NE NJNY OK PA SC TN UT VT W

IW

Y0

1

2

3

4

5

6

7

Total Average Daily Traffic on Bridges

State

Ave

rage

Num

ber

of C

ars (

108)

Bridges on Main Freeways in California

US 101

I-10

I-405

I-210

I-5

I-210 I-10 US 101 I-5 I-4050

200

400

600

800

1000

1200

1400

1600

1800

Number of California Bridges in Each Freeway

Freeway

Cou

nt o

f Bri

dges

I-210 I-10 US 101 I-5 I-4050

20406080

100120140160180

California Bridges and the Number of Structurally Deficient/Func-tionally Obsolete Bridges on the Freeways

Structurally DeficientFunctionally Obsolete

Freeway

Cou

nt o

f Bri

dges

I-210 I-10 US 101 I-5 I-4050

20406080

100120140160

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

Freeway

Cou

nt o

f Bri

dges

050

100150200250300350400

Southern California Interstate and Freeway Bridges

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

County

Cou

nt o

f Bri

dges

Ownership

49%

29%

19%

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

AK AR CA CT DE GA IA IL KS LA MD M

IM

O MT ND NE NJ

NY OK PA SC TN UT VT WI

WY

0

0.5

1

1.5

2

2.5

3

3.5

4Federally and Non-Federally Aided united States Bridges Represented in Count

Federally Aided Highway BridgeNon-Federally Aided Highway Bridge

State

Cou

nt o

f Bri

dges

(104

)

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?