County profile · official public datasets

Addison County, VT

143 public highway bridges tracked in the FHWA National Bridge Inventory: 51.7% rated Good, 45.5% Fair, 2.8% Poor.

Compiled by PlainBridges

143
Public bridges: 51.7%
Good condition: 2.8%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Addison County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

9th
of 14 on Poor share: 2.8%
Poor-condition share: 143
public highway bridges: 1965
avg year built

Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.

Addison County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Addison County ranks #9 of 14 Vermont counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 2.8%). Addison County, Vermont contains 143 public highway bridges. Roughly 51.7% are rated “Good,” 45.5% “Fair,” and 2.8% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.

Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

Total bridges

143

Public highway bridges in Addison County

Good condition

51.7%

74 of 143 rated 7-9

Fair condition

45.5%

65 of 143 rated 5-6

Poor condition

2.8%

4 of 143 rated 4 or below

In-state Poor-share rank

#9 of 14

Among Vermont counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 143 NBI-tracked bridges by lowest applicable component rating.

Good

51.7% (74)

Fair

45.5% (65)

Poor

2.8% (4)

Addison County's Poor-condition bridges carry 11,490 vehicle crossings a day

That is 6.3% of the county's reported daily bridge traffic on 2.8% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 2,873 crossings a day against 891 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.

Computed over the 143 of 143 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

60.8% of Addison County's bridges have passed the 50-year mark

87 of the 143 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 51.7% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.

Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.

One structure carries 93.1% of the county's Poor-condition bridge traffic

VT 0022A ALT over OTTER CREEK, built 1934, carries 10,700 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 4-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 11,490 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

pre-1900

4
1900s

1
1910s

8
1920s

5
1930s

22
1940s

9
1950s

16
1960s

15
1970s

13
1980s

11
1990s

7
2000s

11
2010s

16
2020s

5

What this shows Construction peaked in the 1930s, when 22 of the county's bridges still in the inventory were built, which is 15.4% of those with a recorded year. That cohort is now 85 to 94 years old in the 2024 inventory. Its average build year (1965) matches the Vermont average (1964).

How Addison County compares with Vermont's closest counties by inventory size

The 5 Vermont counties nearest Addison County in number of bridges, with their condition splits. Its 2.8% Poor share is the 5th-lowest of these 6. Its average build year of 1965 against a peer-group mean of 1965 is in line with the group.

Showing the 5 closest of 13 Vermont counties eligible for comparison.

Bridge inventory size and condition shares for Addison County and the 5 Vermont counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Orange County	208	50.5%	47.6%	1.9%	1959
Chittenden County	184	54.9%	42.9%	2.2%	1967
Orleans County	181	52.5%	44.8%	2.8%	1971
Franklin County	149	56.4%	43.6%	0%	1963
Addison County (this page)	143	51.7%	45.5%	2.8%	1965
Lamoille County	127	54.3%	41.7%	3.9%	1964

Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Addison County's. Source: FHWA National Bridge Inventory, 2024 release.

Nationwide counties with similar inventory size or average build year

Two NBI-derived peer sets for Addison County, both outside Vermont so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside VT (143 bridges here).

Franklin County, AR · 143 bridges
San Francisco County, CA · 143 bridges
Woodson County, KS · 143 bridges
Adair County, KY · 143 bridges

Similar average build year

Nearest mean year-built outside VT (1965 here).

Bedford County, PA · avg 1965 · 417 bridges
Crawford County, PA · avg 1965 · 399 bridges
Harper County, KS · avg 1965 · 372 bridges
Columbia County, PA · avg 1965 · 271 bridges

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 143 Good 74 Fair 65 Poor 4

Good-condition bridges (74)

Sort:

Addison County Bridge Snapshot

Condition distribution

Addison County's Poor-condition bridges carry 11,490 vehicle crossings a day

60.8% of Addison County's bridges have passed the 50-year mark

One structure carries 93.1% of the county's Poor-condition bridge traffic

How Addison County compares with Vermont's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

Good-condition bridges (74)

C3035

C2004

C3004

C3012

C2004

C3002

NO DATA ENTERED

VT 00017 ML

C3011

C3008

C3006

VT 00100 ML

C3003

VT 00116 ML

C2001

C3027

C3005

C2005

C3002

C2001

C2001

C3023

C3012

ROAD

C2006

C3050

C2010

VT 00017 ML

VT 00125 ML

C3019

VT 00125 ML

C3004

C3026

C3027

C3010

C3017

C3035

TR 02 FAS 183

C3021

C3014

VT 00116 ML

RTE 185

VT 00017 ML

C3035

C3023

TR 01 FAS 188

C3033 FH13B

C3008

VT 00116 ML

C3002

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