Total bridges
100
Public highway bridges in Monroe County
County profile · official public datasets
Monroe County, FL
100 public highway bridges tracked in the FHWA National Bridge Inventory: 34% rated Good, 59% Fair, 7% Poor.
- 100
- Public bridges
- 34%
- Good condition
- 7%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Monroe 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.
- 54th
- of 67 on Poor share
- 7%
- Poor-condition share
- 100
- public highway bridges
- 1978
- 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.
Monroe County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Monroe County ranks #54 of 67 Florida counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 7%). Monroe County, Florida contains 100 public highway bridges. Roughly 34% are rated “Good,” 59% “Fair,” and 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.
Good condition
34%
34 of 100 rated 7-9
Fair condition
59%
59 of 100 rated 5-6
Poor condition
7%
7 of 100 rated 4 or below
In-state Poor-share rank
#54 of 67
Among Florida counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 100 NBI-tracked bridges by lowest applicable component rating.
Good 34% (34)
Fair 59% (59)
Poor 7% (7)
Monroe County's Poor-condition bridges carry 9,482 vehicle crossings a day
That is 1% of the county's reported daily bridge traffic on 6.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,580 crossings a day against 12,022 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 99 of 100 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
38% of Monroe County's bridges have passed the 50-year mark
38 of the 100 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 34% 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 33.6% of the county's Poor-condition bridge traffic
Card Sound Road over Tubbys Creek, built 1969, carries 3,182 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 7-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 9,482 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Monroe County's bridges were built
100 bridges with a recorded construction year, grouped by decade
- 1910s 1
1910–1919
1 bridges
- 1930s 1
1930–1939
1 bridges
- 1950s 8
1950–1959
8 bridges
- 1960s
1960–1969
24 bridges
- 1970s 11
1970–1979
11 bridges
- 1980s
1980–1989
36 bridges
- 1990s 5
1990–1999
5 bridges
- 2000s 13
2000–2009
13 bridges
- 2010s 1
2010–2019
1 bridges
What this shows Construction peaked in the 1980s, when 36 of the county's bridges still in the inventory were built, which is 36% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1978, 5 years older than the Florida average of 1983.
How Monroe County compares with Florida's closest counties by inventory size
The 5 Florida counties nearest Monroe County in number of bridges, with their condition splits. Its 7% Poor share is the 4th-lowest of these 6. Its average build year of 1978 against a peer-group mean of 1978 is in line with the group.
Showing the 5 closest of 66 Florida counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Flagler County | 105 | 57.1% | 41% | 1.9% | 1981 |
| Nassau County | 104 | 49% | 48.1% | 2.9% | 1977 |
| Monroe County (this page) | 100 | 34% | 59% | 7% | 1978 |
| Washington County | 99 | 43.4% | 46.5% | 10.1% | 1984 |
| Baker County | 93 | 26.9% | 64.5% | 8.6% | 1966 |
| Clay County | 90 | 47.8% | 48.9% | 3.3% | 1984 |
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 Monroe 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 Monroe County, both outside Florida so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside FL (100 bridges here).
- Ketchikan Gateway County, AK · 100 bridges
- Gunnison County, CO · 100 bridges
- Fayette County, IN · 100 bridges
- LaGrange County, IN · 100 bridges
Similar average build year
Nearest mean year-built outside FL (1978 here).
- Orange County, CA · avg 1978 · 1,164 bridges
- Sumner County, KS · avg 1978 · 659 bridges
- Allen County, IN · avg 1978 · 613 bridges
- Livingston County, IL · avg 1978 · 579 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Good-condition bridges (34)
Ramp to Pigeon Key
GoodOver: Pigeon Key
Pigeon Key, Monroe, FL
Built 1938 Load: 0.0 t ADT: 101
US 1 (SR 5)
GoodOver: TOMS HARBOR CHANNEL
DUCK KEY (MM 60.4), Monroe, FL
Built 1980 Load: 29.8 t ADT: 12,700
Watson Blvd Old
GoodOver: Watson Cut
2 miles W of SR5 MM 30.5, Monroe, FL
Built 1960 Load: 30.5 t ADT: 2,060
117th Street
GoodOver: Vaca Channel # 1
200Ft. S of US1 MM 53.1, Monroe, FL
Built 1967 Load: 32.7 t ADT: 288
WATSON RD
GoodOver: TIDAL SLOUGH
BIG PINE KEY, Monroe, FL
Built 2001 Load: 32.7 t ADT: 40
Shore Drive
GoodOver: Canal
0.2 Mile E of US1 MM17, Monroe, FL
Built 1991 Load: 33.6 t ADT: 237
US 1 (SR 5)
GoodOver: NAVAL BASE BLVD
NORTH OF KEY WEST (MM8.0), Monroe, FL
Built 1988 Load: 35.1 t ADT: 27,500
Watson Blvd
GoodOver: Un-Named Channel
0.5Mi. N of Key Deer Blvd, Monroe, FL
Built 1965 Load: 35.9 t ADT: 2,060
US 1 (SR 5)
GoodOver: SADDLE BUNCH #5
N BOCA CHICA KEY(MM 12.5), Monroe, FL
Built 1980 Load: 37.0 t ADT: 16,900
US 1 NB (900130)
GoodOver: MARVIN D. ADAMS WATERWAY
KEY LARGO (MM 103.6), Monroe, FL
Built 1973 Load: 37.4 t ADT: 15,126
SR-5 (US-1)
GoodOver: Snake Creek Canal
Plantation Key (MM 85.5), Monroe, FL
Built 1981 Load: 37.6 t ADT: 20,700
US-1 NB (900125)
GoodOver: COW KEY CHANNEL
KEY WEST (MM 4.1), Monroe, FL
Built 1978 Load: 38.2 t ADT: 23,000
US 1 (SR 5)
GoodOver: ROCKLAND CHANNEL
BOCA CHICA KEY (MM 9.6), Monroe, FL
Built 1979 Load: 38.7 t ADT: 47,000
US 1 NB (900003)
GoodOver: BOCA CHICA CHANNEL
BOCA CHICA KEY (MM 6.0), Monroe, FL
Built 1982 Load: 39.4 t ADT: 13,500
US 1 (SR 5)
GoodOver: JEWFISH CREEK
NB OFF RAMP TO ROTARY, Monroe, FL
Built 2008 Load: 39.6 t ADT: 100
US 1 (SR 5)
GoodOver: JEWFISH CREEK
NB OFF RAMP TO US-1, Monroe, FL
Built 2008 Load: 39.6 t ADT: 80
Palm Drive
GoodOver: Bay Point Canal
0.3 Mile E of US-1 MM14.8, Monroe, FL
Built 1975 Load: 39.8 t ADT: 593
US 1 (SR 5)
GoodOver: LIGNUMVITAE CHANNEL
MATECUMBE KEY (MM 77.5), Monroe, FL
Built 1981 Load: 40.3 t ADT: 15,800
SR-A1A (Key West)
GoodOver: RIVIERA CANAL
SR A1A (MM 2.5), Monroe, FL
Built 1960 Load: 40.5 t ADT: 12,300
US 1 (SR 5)
GoodOver: HARRIS GAP CHANNEL
SUGARLOAF KEY (MM 17.5), Monroe, FL
Built 1982 Load: 40.5 t ADT: 17,600
US 1 SB (900073)
GoodOver: MARVIN D. ADAMS WATERWAY
KEY LARGO (MM 103.6), Monroe, FL
Built 1993 Load: 40.6 t ADT: 15,126
US 1 (SR 5)
GoodOver: PARK CHANNEL
SUGARLOAF KEY (MM 18.6), Monroe, FL
Built 1982 Load: 41.7 t ADT: 17,600
US 1 (SR 5)
GoodOver: JEWFISH CREEK
SB ON RAMP TO US-1, Monroe, FL
Built 2008 Load: 43.4 t ADT: 150
US 1 (SR 5)
GoodOver: JEWFISH CREEK
SB OFF RAMP TO ROTARY, Monroe, FL
Built 2007 Load: 43.5 t ADT: 60
US 1(SR 5)FRNTG RD
GoodOver: CROCODILE CROSSING
JUST N/O JEWFISH CREEK, Monroe, FL
Built 2008 Load: 44.1 t ADT: 400
US 1 (SR 5)
GoodOver: SOUTH PINE CHANNEL
N OF TORCH KEY (MM 28.8), Monroe, FL
Built 1982 Load: 45.0 t ADT: 18,000
Bimini Drive
GoodOver: Sams Canal
1Mile E of SR5 at MM 61.1, Monroe, FL
Built 1955 Load: 45.1 t ADT: 539
US 1 (SR 5)
GoodOver: JEWFISH CREEK
US 1 (M.M. 107), Monroe, FL
Built 2008 Load: 47.0 t ADT: 26,500
US 1 (SR 5)
GoodOver: SADDLE BUNCH #3 CHANNEL
N BOCA CHICA KEY (MM14.2), Monroe, FL
Built 1981 Load: 47.4 t ADT: 17,600
US-1 (SR 5)
GoodOver: WHALE HARBOR
ISLAMORADA KEY (MM 83.8), Monroe, FL
Built 1951 Load: 48.6 t ADT: 20,700
US-1 SB (900086)
GoodOver: COW KEY CHANNEL
KEY WEST (MM 4.1), Monroe, FL
Built 1985 Load: 49.4 t ADT: 23,000
US 1 (SR 5)
GoodOver: FIRST DEER CROSSING
BIG PINE KEY (MM 31.4), Monroe, FL
Built 2002 Load: 52.5 t ADT: 13,200
US 1 (SR 5)
GoodOver: SECOND DEER CROSSING
BIG PINE KEY (MM 32.4), Monroe, FL
Built 2002 Load: 52.5 t ADT: 13,200
US 1 SB (900078)
GoodOver: TAVERNIER CREEK
TAVERNIER KEY (MM 90.8), Monroe, FL
Built 1993 Load: 56.0 t ADT: 15,000
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.