County profile · official public datasets

Hillsborough County, FL

840 public highway bridges tracked in the FHWA National Bridge Inventory: 68.8% rated Good, 31% Fair, 0.2% Poor.

840
Public bridges: 68.8%
Good condition: 0.2%
Poor condition

The verdict

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

Hillsborough County posts a top-quartile lowest Poor-condition share among rated counties in the state across large county bridge inventory.

Top 19%
lowest Poor share in state: 0.2%
Poor-condition share: 840
public highway bridges: 1985
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.

Hillsborough County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Hillsborough County ranks #13 of 67 Florida counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 0.2%). Hillsborough County, Florida contains 840 public highway bridges. Roughly 68.8% are rated “Good,” 31% “Fair,” and 0.2% “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.

Total bridges

840

Public highway bridges in Hillsborough County

Good condition

68.8%

578 of 840 rated 7-9

Fair condition

31%

260 of 840 rated 5-6

Poor condition

0.2%

2 of 840 rated 4 or below

In-state Poor-share rank

#13 of 67

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

Condition distribution

Share of 840 NBI-tracked bridges by lowest applicable component rating.

Good

68.8% (578)

Fair

31% (260)

Poor

0.2% (2)

Hillsborough County's Poor-condition bridges carry 970 vehicle crossings a day

That is 0% of the county's reported daily bridge traffic on 0.2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 485 crossings a day against 32,922 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 840 of 840 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

29.8% of Hillsborough County's bridges have passed the 50-year mark

250 of the 840 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 68.8% 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 76.3% of the county's Poor-condition bridge traffic

NEWBERGER ROAD over KELL CREEK, built 1947, carries 740 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 2-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 970 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

2
1920s

11
1930s

10
1940s

10
1950s

19
1960s

144
1970s

126
1980s

163
1990s

133
2000s

113
2010s

79
2020s

30

What this shows Construction peaked in the 1980s, when 163 of the county's bridges still in the inventory were built, which is 19.4% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1985) matches the Florida average (1983).

How Hillsborough County compares with Florida's closest counties by inventory size

The 5 Florida counties nearest Hillsborough County in number of bridges, with their condition splits. Its 0.2% Poor share is the 2nd-lowest of these 6. Its average build year of 1985 against a peer-group mean of 1986 is in line with the group.

Showing the 5 closest of 66 Florida counties eligible for comparison.

Bridge inventory size and condition shares for Hillsborough County and the 5 Florida counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Miami-Dade County	1,057	69.5%	25.7%	4.7%	1980
Orange County	885	75.6%	24.3%	0.1%	1998
Hillsborough County (this page)	840	68.8%	31%	0.2%	1985
Duval County	831	63.7%	34.5%	1.8%	1984
Broward County	686	69.2%	28.9%	1.9%	1982
Palm Beach County	610	79.7%	20%	0.3%	1987

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 Hillsborough 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 Hillsborough County, both outside Florida so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside FL (840 bridges here).

Davidson County, TN · 832 bridges
Montgomery County, PA · 828 bridges
Middlesex County, MA · 818 bridges
Cuyahoga County, OH · 871 bridges

Similar average build year

Nearest mean year-built outside FL (1985 here).

Lancaster County, NE · avg 1985 · 661 bridges
Nueces County, TX · avg 1985 · 528 bridges
Grayson County, TX · avg 1985 · 513 bridges
Douglas County, NE · avg 1985 · 509 bridges

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

All 840 Good 578 Fair 260 Poor 2

Good-condition bridges (578)

Sort:

Hillsborough County Bridge Snapshot

Condition distribution

Hillsborough County's Poor-condition bridges carry 970 vehicle crossings a day

29.8% of Hillsborough County's bridges have passed the 50-year mark

One structure carries 76.3% of the county's Poor-condition bridge traffic

How Hillsborough County compares with Florida'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 (578)

WATERS AVE

US-301 (SR-43)

US-301 (SR-43 NB)

SR618 SELMON WB

SR 589 VET SB 7.9

US-301 (SR-41)

RAMPS E & K

RAMP B

I-4 On Ramp

I-75 NB RAMP B-3

SR618Bto/fromSR618

CR-579 (M.B.R.)

BOYETTE RD

CAUSEWAY BLVD

I-4 WB

XTOWN (SR-618) WB

GALLAGHER ROAD

I-4 EB

US-301 NB (SR-43)

I-4 WB

I-275

I-4WB TO DNTWN RMP

SR 589 VET SB 4.4

RAMP R/DALE MABRY

NESMITH RD.

CR-39

I-275 NB (SR-93)

I-75 (SR-93) SB

I-4 EB RAMP B

I-75 SB

CR580 SAM ALLEN RD

VIADUCT RAMP E

SR 589 VET NB 4.4

SR616WB-SR60WB

I-75 SB (SR-93A)

SR618A SELMON EXPY

COUNTY LINE RD

SR 589 VET NB 3.8

SR 589 VET SB 5.0

SR 589 VET NB 5.0

SR 589 VET NB 6.5

US-301

I-275 NB

I-275NB RP toUS-92

I-75 SB TO SR-60

BIG BEND ROAD

SR589 (VETERANS SB

SR618 EB to I-4 EB

CR 581 NB

US-301 (SR-43)

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