Total bridges
277
Public highway bridges in Porter County
County profile · official public datasets
Porter County, IN
277 public highway bridges tracked in the FHWA National Bridge Inventory: 42.6% rated Good, 52% Fair, 5.4% Poor.
- 277
- Public bridges
- 42.6%
- Good condition
- 5.4%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Porter County pairs a higher-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.
- 55th
- of 92 on Poor share
- 5.4%
- Poor-condition share
- 277
- public highway bridges
- 1970
- 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.
Porter County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Porter County ranks #55 of 92 Indiana counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 5.4%). Porter County, Indiana contains 277 public highway bridges. Roughly 42.6% are rated “Good,” 52% “Fair,” and 5.4% “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.
Good condition
42.6%
118 of 277 rated 7-9
Fair condition
52%
144 of 277 rated 5-6
Poor condition
5.4%
15 of 277 rated 4 or below
In-state Poor-share rank
#55 of 92
Among Indiana counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 277 NBI-tracked bridges by lowest applicable component rating.
Good 42.6% (118)
Fair 52% (144)
Poor 5.4% (15)
Porter County's Poor-condition bridges carry 25,367 vehicle crossings a day
That is 1% of the county's reported daily bridge traffic on 5.4% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,691 crossings a day against 11,027 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 277 of 277 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
63.5% of Porter County's bridges have passed the 50-year mark
176 of the 277 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 42.6% 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 20.2% of the county's Poor-condition bridge traffic
WAVERLY ROAD over LITTLE CALUMET RIVER, built 1966, carries 5,130 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 15-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 25,367 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Porter County's bridges were built
277 bridges with a recorded construction year, grouped by decade
- 1910s 1
1910–1919
1 bridges
- 1920s 4
1920–1929
4 bridges
- 1930s
1930–1939
40 bridges
- 1940s 3
1940–1949
3 bridges
- 1950s
1950–1959
48 bridges
- 1960s
1960–1969
49 bridges
- 1970s
1970–1979
36 bridges
- 1980s
1980–1989
37 bridges
- 1990s 18
1990–1999
18 bridges
- 2000s 12
2000–2009
12 bridges
- 2010s
2010–2019
21 bridges
- 2020s 8
2020–2029
8 bridges
What this shows Construction peaked in the 1960s, when 49 of the county's bridges still in the inventory were built, which is 17.7% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1970, 8 years older than the Indiana average of 1978.
How Porter County compares with Indiana's closest counties by inventory size
The 5 Indiana counties nearest Porter County in number of bridges, with their condition splits. Its 5.4% Poor share is the 5th-lowest of these 6. Its average build year of 1970 against a peer-group mean of 1978 is 8 years older.
Showing the 5 closest of 91 Indiana counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Grant County | 280 | 38.6% | 59.6% | 1.8% | 1975 |
| Vanderburgh County | 279 | 47.7% | 48% | 4.3% | 1980 |
| Elkhart County | 278 | 38.1% | 55.8% | 6.1% | 1975 |
| Delaware County | 277 | 31.8% | 62.8% | 5.4% | 1976 |
| Porter County (this page) | 277 | 42.6% | 52% | 5.4% | 1970 |
| Bartholomew County | 269 | 53.5% | 43.1% | 3.3% | 1982 |
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 Porter 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 Porter County, both outside Indiana so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside IN (277 bridges here).
- Navajo County, AZ · 277 bridges
- Shelby County, OH · 277 bridges
- Florence County, SC · 277 bridges
- Edgar County, IL · 278 bridges
Similar average build year
Nearest mean year-built outside IN (1970 here).
- Hamilton County, OH · avg 1970 · 783 bridges
- Yavapai County, AZ · avg 1970 · 543 bridges
- Garfield County, OK · avg 1970 · 504 bridges
- San Luis Obispo County, CA · avg 1970 · 401 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Poor-condition bridges (15)
MINERAL SPRING
PoorOver: LITTLE CALUMET RIVER
00.40 N BEAM ST., Porter, IN
Built 1964 Load: 5.2 t ADT: 400
CR 1000S
PoorOver: REEVES DITCH
01.00 E CR 600 E, Porter, IN
Built 1930 Load: 14.3 t ADT: 80
CR 600N
PoorOver: SALT CREEK
00.25 W JCT SR 149, Porter, IN
Built 1970 Load: 16.5 t ADT: 1,670
CR 300S
PoorOver: LUDINGTON DITCH
00.40 E CR 500 W, Porter, IN
Built 1972 Load: 20.7 t ADT: 340
SR 249/G NELSON DR
PoorOver: US 12 2 RR 2 ROADS
02.00 N I-94, Porter, IN
Built 2000 Load: 21.4 t ADT: 4,256
CR 200W
PoorOver: DAMON RUN
00.70 N U.S. 6, Porter, IN
Built 1968 Load: 22.0 t ADT: 3,230
WILSON ROAD
PoorOver: DUNES CREEK
00.00 DUNES STATE PARK, Porter, IN
Built 1934 Load: 23.0 t ADT: 143
CR 300W
PoorOver: CORNELL DITCH
00.60 N 750 S, Porter, IN
Built 1930 Load: 25.3 t ADT: 110
CR 1050S
PoorOver: PLEASANT TOWNSHIP DITCH
00.50 W CR 50 E, Porter, IN
Built 1930 Load: 26.2 t ADT: 200
CR 600E
PoorOver: CROOKED CREEK
00.70 N 200 N, Porter, IN
Built 1971 Load: 26.6 t ADT: 80
WAVERLY ROAD
PoorOver: LITTLE CALUMET RIVER
00.10 N ACKERMAN RD, Porter, IN
Built 1966 Load: 27.2 t ADT: 5,130
LENBURG ROAD
PoorOver: SALT CREEK
00.30 E MCCOOL RD, Porter, IN
Built 1968 Load: 28.6 t ADT: 3,140
DIVISION ROAD
PoorOver: HUTTON DITCH
00.40 W CR 575 E, Porter, IN
Built 1961 Load: 32.4 t ADT: 190
US 12 EB
PoorOver: BURNS DITCH (DEEP RIVER)
00.94 W SR 249, Porter, IN
Built 1970 Load: 42.4 t ADT: 4,635
US 12 WB
PoorOver: BURNS DITCH (DEEP RIVER)
00.94 W SR 249, Porter, IN
Built 1970 Load: 42.4 t ADT: 1,763
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.