US Bridges

US 30 over Mississippi Rvr RR S 2nd

Fair

Clinton County, Iowa · In Clinton · Structure no. 000000000020860

Built
1956
69 years old, rebuilt 1999
Condition
Fair
inspected November 2024
Type
Suspension
Steel
Length
4,165 ft
1 main span
Daily traffic
11,100
2022 count
Owner
State
State Highway Agency

About this bridge

US 30 over Mississippi Rvr RR S 2nd is a steel suspension carrying US 30 over Mississippi Rvr RR S 2nd in Clinton County, Iowa. It was built in 1956 and reconstructed in 1999, so it is 69 years old, older than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 11,100 vehicles a day, roughly 11% of them trucks, projected to reach 11,100 by 2044. The structure is 4,165 ft (1,269.5 m) long and 33 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesUS 30
CrossesMississippi Rvr RR S 2nd
LocationIn Clinton
RouteU.S. Route 30
CountyClinton County
StateIowa
Coordinates41.83781, -90.19048
Functional classUrban Other Principal Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating50 US tons
Inventory rating30 US tons

Structure

Structure typeSuspension
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+30 approach)
Design loadHS 20
Structure length4,165 ft (1,269.5 m)
Longest span644 ft (196.3 m)
Deck width33 ft (10 m)
Roadway width29 ft (8.9 m)
Vertical clearance over deck32 ft (9.8 m)

Traffic and service

Average daily traffic11,100 (2022)
Projected traffic11,100 by 2044
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad and waterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was US 30 over Mississippi Rvr RR S 2nd built?

It was built in 1956, making it 69 years old in 2025. It was reconstructed in 1999.

What condition is US 30 over Mississippi Rvr RR S 2nd in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in November 2024.

How much traffic does US 30 over Mississippi Rvr RR S 2nd carry?

About 11,100 vehicles per day (2022 count), of which roughly 11% are trucks.

How long is US 30 over Mississippi Rvr RR S 2nd?

The structure is 4,165 ft (1,269.5 m) long with a longest span of 644 ft (196.3 m) and a deck 33 ft wide.

Who owns US 30 over Mississippi Rvr RR S 2nd?

It is owned by the State Highway Agency.