US Bridges

IH 45 Sbml over Dickinson Bayou

Fair

Galveston County, Texas · 0.30 MI SE of FM 517 · Structure no. 120850050004030

Built
1948
77 years old, rebuilt 1977
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
292 ft
7 main spans
Daily traffic
46,207
2023 count
Owner
State
State Highway Agency

About this bridge

IH 45 Sbml over Dickinson Bayou is a steel stringer/multi-beam or girder carrying IH 45 Sbml over Dickinson Bayou in Galveston County, Texas. It was built in 1948 and reconstructed in 1977, so it is 77 years old, older than the Texas average of 44.4 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 46,207 vehicles a day, roughly 6% of them trucks, projected to reach 59,870 by 2033. The structure is 292 ft (89 m) long and 66 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesIH 45 Sbml
CrossesDickinson Bayou
Location0.30 MI SE of FM 517
RouteInterstate 45
CountyGalveston County
StateTexas
Coordinates29.44526, -95.07403
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating61.9 US tons
Inventory rating37 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans7
Design loadHS 20
Structure length292 ft (89 m)
Longest span50 ft (15.2 m)
Deck width66 ft (20.1 m)
Roadway width64 ft (19.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic46,207 (2023)
Projected traffic59,870 by 2033
Trucks6%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was IH 45 Sbml over Dickinson Bayou built?

It was built in 1948, making it 77 years old in 2025. It was reconstructed in 1977.

What condition is IH 45 Sbml over Dickinson Bayou 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 September 2024.

How much traffic does IH 45 Sbml over Dickinson Bayou carry?

About 46,207 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is IH 45 Sbml over Dickinson Bayou?

The structure is 292 ft (89 m) long with a longest span of 50 ft (15.2 m) and a deck 66 ft wide.

Who owns IH 45 Sbml over Dickinson Bayou?

It is owned by the State Highway Agency.