County profile · official public datasets

St. Louis city County, MO

240 public highway bridges tracked in the FHWA National Bridge Inventory: 31.3% rated Good, 58.8% Fair, 10% Poor.

240
Public bridges: 31.3%
Good condition: 10%
Poor condition

The verdict

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

St. Louis city County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

69th
of 115 on Poor share: 10%
Poor-condition share: 240
public highway bridges: 1982
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.

St. Louis city County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, St. Louis city County ranks #69 of 115 Missouri counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 10%). St. Louis city County, Missouri contains 240 public highway bridges. Roughly 31.3% are rated “Good,” 58.8% “Fair,” and 10% “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

240

Public highway bridges in St. Louis city County

Good condition

31.3%

75 of 240 rated 7-9

Fair condition

58.8%

141 of 240 rated 5-6

Poor condition

10%

24 of 240 rated 4 or below

In-state Poor-share rank

#69 of 115

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

Condition distribution

Share of 240 NBI-tracked bridges by lowest applicable component rating.

Good

31.3% (75)

Fair

58.8% (141)

Poor

10% (24)

St. Louis city County's Poor-condition bridges carry 432,045 vehicle crossings a day

That is 7.9% of the county's reported daily bridge traffic on 10% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 18,002 crossings a day against 20,204 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 240 of 240 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

45% of St. Louis city County's bridges have passed the 50-year mark

108 of the 240 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 31.3% 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.

One structure carries 12.4% of the county's Poor-condition bridge traffic

IS 44 W over CST PARK AVE MO 100, built 1976, carries 53,654 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 24-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 432,045 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

pre-1900

1
1910s

5
1920s

3
1930s

8
1950s

11
1960s

59
1970s

32
1980s

19
1990s

20
2000s

38
2010s

35
2020s

9

What this shows Construction peaked in the 1960s, when 59 of the county's bridges still in the inventory were built, which is 24.6% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1982) matches the Missouri average (1979).

How St. Louis city County compares with Missouri's closest counties by inventory size

The 5 Missouri counties nearest St. Louis city County in number of bridges, with their condition splits. Its 10% Poor share is the 4th-lowest of these 6. Its average build year of 1982 against a peer-group mean of 1983 is in line with the group.

Showing the 5 closest of 114 Missouri counties eligible for comparison.

Bridge inventory size and condition shares for St. Louis city County and the 5 Missouri counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Buchanan County	246	34.1%	58.1%	7.7%	1981
Gentry County	246	52%	33.3%	14.6%	1992
Pettis County	243	43.6%	45.3%	11.1%	1975
St. Louis city County (this page)	240	31.3%	58.8%	10%	1982
Lafayette County	238	31.9%	65.5%	2.5%	1980
DeKalb County	237	35%	56.5%	8.4%	1985

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 St. Louis city 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 St. Louis city County, both outside Missouri so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside MO (240 bridges here).

Jefferson Davis County, LA · 240 bridges
Carroll County, TN · 240 bridges
Marshall County, TN · 240 bridges
Sheboygan County, WI · 240 bridges

Similar average build year

Nearest mean year-built outside MO (1982 here).

Oklahoma County, OK · avg 1982 · 1,216 bridges
Milwaukee County, WI · avg 1982 · 893 bridges
Champaign County, IL · avg 1982 · 727 bridges
Broward County, FL · avg 1982 · 686 bridges

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

All 240 Good 75 Fair 141 Poor 24

All bridges (240)

Sort:

St. Louis city County Bridge Snapshot

Condition distribution

St. Louis city County's Poor-condition bridges carry 432,045 vehicle crossings a day

45% of St. Louis city County's bridges have passed the 50-year mark

One structure carries 12.4% of the county's Poor-condition bridge traffic

How St. Louis city County compares with Missouri's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

All bridges (240)

IS 270 E

IS 55 S

JEFFERSON AVE S

IS 55 N

MORGANFORD RD

SUBLETTE AVE

18TH ST

ARSENAL ST E

RP S 7TH BLVD TO I

COMPTON AVE S

DELMAR BLVD

MARKET ST E

IS 64 E

IS 55 S

IS 55 N

IS 55 S

SIDNEY ST E

IS 70 E

LAMBERT INTL BLVD

JAMIESON AVE S

IS 64 W

IS 64 E

IS 55 S

RP IS44E TO LAFAYE

RP IS55N TO TRUMAN

R. DES PERES DR

GERMANIA RD

IS 44 E

IS 44 W

JAMIESON AVE N

IS 70 E

IS 55 S

18TH ST

IS 55 S

HAMPTON AVE

TOWER GROVE AVE

VANDEVENTER AVE

BROADWAY AVE

14TH ST

RP MARKET ST TO IS

COLLECTOR DR

MO 366 E

IS 270 W

RP IS55N TO IS44W

IS 44 E

IS 70 E

KINGSHIGHWAY BLVD

IS 55 N

IS 55 S

EDWARDS ST S

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