Total bridges
215
Public highway bridges in Terrebonne County
County profile · official public datasets
215 public highway bridges tracked in the FHWA National Bridge Inventory: 42.3% rated Good, 47% Fair, 10.7% Poor.
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Terrebonne County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.
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.
According to the Federal Highway Administration's 2024 National Bridge Inventory, Terrebonne County ranks #33 of 64 Louisiana counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 10.7%). Terrebonne County, Louisiana contains 215 public highway bridges. Roughly 42.3% are rated “Good,” 47% “Fair,” and 10.7% “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
215
Public highway bridges in Terrebonne County
Good condition
42.3%
91 of 215 rated 7-9
Fair condition
47%
101 of 215 rated 5-6
Poor condition
10.7%
23 of 215 rated 4 or below
In-state Poor-share rank
#33 of 64
Among Louisiana counties with 5+ bridges, lower share ranks better
Share of 215 NBI-tracked bridges by lowest applicable component rating.
That is 8.1% of the county's reported daily bridge traffic on 10.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 3,545 crossings a day against 4,595 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 215 of 215 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
80 of the 215 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 42.3% 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.
N. HOLLYWOOD RD over DRAIN CANAL, built 1965, carries 13,934 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 23-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 81,537 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
215 bridges with a recorded construction year, grouped by decade
1930–1939
2 bridges
1940–1949
3 bridges
1950–1959
14 bridges
1960–1969
35 bridges
1970–1979
42 bridges
1980–1989
33 bridges
1990–1999
53 bridges
2000–2009
9 bridges
2010–2019
21 bridges
2020–2029
3 bridges
What this shows Construction peaked in the 1990s, when 53 of the county's bridges still in the inventory were built, which is 24.7% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year (1983) matches the Louisiana average (1982).
The 5 Louisiana counties nearest Terrebonne County in number of bridges, with their condition splits. Its 10.7% Poor share is the 2nd-lowest of these 6. Its average build year of 1983 against a peer-group mean of 1982 is in line with the group.
Showing the 5 closest of 63 Louisiana counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Beauregard County | 221 | 13.6% | 78.3% | 8.1% | 1979 |
| Winn County | 220 | 55.5% | 28.2% | 16.4% | 1987 |
| Ascension County | 216 | 41.2% | 45.8% | 13% | 1981 |
| Terrebonne County (this page) | 215 | 42.3% | 47% | 10.7% | 1983 |
| Grant County | 209 | 41.6% | 42.6% | 15.8% | 1982 |
| Richland County | 207 | 21.3% | 67.6% | 11.1% | 1979 |
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 Terrebonne County's. Source: FHWA National Bridge Inventory, 2024 release.
Two NBI-derived peer sets for Terrebonne County, both outside Louisiana so the neighborhoods are not the same-state size table above.
Nearest county inventories outside LA (215 bridges here).
Nearest mean year-built outside LA (1983 here).
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Over: COULEE
0.004 MI W OF DEADWOOD RD, Terrebonne, LA
Over: CHAUVIN BAYOU
0057 LOG MI FROM IN, Terrebonne, LA
Over: CO. CANAL (BOURG)
1.20 MI W OF LA 24, Terrebonne, LA
Over: GRAND CAILLOU BAYOU
0.2 MI E OF LA 57, Terrebonne, LA
Over: HANSON CANAL
00.82 N. of LA 182, Terrebonne, LA
Over: GRAND CAILLOU BAYOU
0.04 MI W OF LA 57, Terrebonne, LA
Over: DRAINAGE CANAL
.36 MI EAST OF LA 56, Terrebonne, LA
Over: BAYOU TERREBONNE
0.01 M W OF EAST PARK, Terrebonne, LA
Over: FALGOUT CANAL
11.0 MI SOUTH OF LA 661, Terrebonne, LA
Over: PROVOST BAYOU
8.6 MI SOUTH OF LA 661, Terrebonne, LA
Over: ST LOUIS CANAL
0005 LOG MI FROM INT, Terrebonne, LA
Over: HOUMA CANAL
.4 MI EAST OF LA 182, Terrebonne, LA
Over: CHACAHOULA CANAL
0.01M W OF DEADWOOD RD, Terrebonne, LA
Over: DRAIN CANAL
0.6 MI. W. OF LA 182, Terrebonne, LA
Over: DU LARGE BAYOU
0.01 MI W OF LA 315, Terrebonne, LA
Read our methodology - how this data is sourced, computed, and verified.
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.