Total bridges
153
Public highway bridges in Sussex County
County profile · official public datasets
Sussex County, DE
153 public highway bridges tracked in the FHWA National Bridge Inventory: 40.5% rated Good, 57.5% Fair, 2% Poor.
- 153
- Public bridges
- 40.5%
- Good condition
- 2%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Sussex County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- 3rd
- of 3 on Poor share
- 2%
- Poor-condition share
- 153
- public highway bridges
- 1974
- 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.
Sussex County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Sussex County ranks #3 of 3 Delaware counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 2%). Sussex County, Delaware contains 153 public highway bridges. Roughly 40.5% are rated “Good,” 57.5% “Fair,” and 2% “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
40.5%
62 of 153 rated 7-9
Fair condition
57.5%
88 of 153 rated 5-6
Poor condition
2%
3 of 153 rated 4 or below
In-state Poor-share rank
#3 of 3
Among Delaware counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 153 NBI-tracked bridges by lowest applicable component rating.
Good 40.5% (62)
Fair 57.5% (88)
Poor 2% (3)
Sussex County's Poor-condition bridges carry 7,832 vehicle crossings a day
That is 0.8% of the county's reported daily bridge traffic on 2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 2,611 crossings a day against 5,414 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 153 of 153 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
50.3% of Sussex County's bridges have passed the 50-year mark
77 of the 153 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 40.5% 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 96.5% of the county's Poor-condition bridge traffic
SR 54 over ASSAWOMAN BAY, built 1957, carries 7,555 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 3-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 7,832 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Sussex County's bridges were built
153 bridges with a recorded construction year, grouped by decade
- 1910s 6
1910–1919
6 bridges
- 1920s 7
1920–1929
7 bridges
- 1930s 9
1930–1939
9 bridges
- 1940s 7
1940–1949
7 bridges
- 1950s
1950–1959
16 bridges
- 1960s
1960–1969
24 bridges
- 1970s
1970–1979
12 bridges
- 1980s
1980–1989
25 bridges
- 1990s
1990–1999
13 bridges
- 2000s 9
2000–2009
9 bridges
- 2010s
2010–2019
19 bridges
- 2020s 6
2020–2029
6 bridges
What this shows Construction peaked in the 1980s, when 25 of the county's bridges still in the inventory were built, which is 16.3% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1974) matches the Delaware average (1977).
How Sussex County compares with Delaware's closest counties by inventory size
The 2 Delaware counties nearest Sussex County in number of bridges, with their condition splits. Its 2% Poor share is the 3rd-lowest of these 3. Its average build year of 1974 against a peer-group mean of 1980 is 6 years older.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| New Castle County | 527 | 34.9% | 64.1% | 0.9% | 1976 |
| Kent County | 192 | 55.7% | 42.7% | 1.6% | 1983 |
| Sussex County (this page) | 153 | 40.5% | 57.5% | 2% | 1974 |
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 Sussex 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 Sussex County, both outside Delaware so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside DE (153 bridges here).
- Jefferson County, IN · 153 bridges
- Harrison County, KY · 153 bridges
- Roger Mills County, OK · 153 bridges
- Perry County, TN · 153 bridges
Similar average build year
Nearest mean year-built outside DE (1974 here).
- Knox County, TN · avg 1974 · 588 bridges
- Summit County, OH · avg 1974 · 563 bridges
- Onondaga County, NY · avg 1974 · 472 bridges
- Orange County, NY · avg 1974 · 472 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
All bridges (153)
CODS ROAD
PoorOver: SLAUGHTER CREEK
WEST OF FOWLER BEACH, Sussex, DE
Built 1931 Load: 16.2 t ADT: 77
CRAIGS MILL RD
PoorOver: CRAIGS POND SPILLWAY
WEST OF SEAFORD, Sussex, DE
Built 1973 Load: 32.7 t ADT: 200
SR 54
PoorOver: ASSAWOMAN BAY
FENWICK ISLAND, Sussex, DE
Built 1957 Load: 43.1 t ADT: 7,555
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.