US Bridges

IH 45 NB Exit over Allen Parkway

Fair

Harris County, Texas · 0.20 MI N of Dallas ST · Structure no. 121020050003217

Built
1955
70 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
443 ft
3 main spans
Daily traffic
6,591
2024 count
Owner
State
State Highway Agency

About this bridge

IH 45 NB Exit over Allen Parkway is a steel continuous stringer/multi-beam or girder carrying IH 45 NB Exit over Allen Parkway in Harris County, Texas. It was built in 1955, so it is 70 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 6,591 vehicles a day, roughly 7% of them trucks, projected to reach 30,220 by 2033. The structure is 443 ft (135 m) long and 25 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesIH 45 NB Exit
CrossesAllen Parkway
Location0.20 MI N of Dallas ST
RouteState Highway 45
CountyHarris County
StateTexas
Coordinates29.76034, -95.37386
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44 US tons
Inventory rating26 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+7 approach)
Design loadHS 20
Structure length443 ft (135 m)
Longest span63 ft (19.2 m)
Deck width25 ft (7.5 m)
Roadway width22 ft (6.6 m)
Vertical clearance over deck15 ft (4.5 m)

Traffic and service

Average daily traffic6,591 (2024)
Projected traffic30,220 by 2033
Trucks7%
Lanes on structure1
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo
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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost$24,000
NavigationNot applicable (no waterway)

Frequently asked questions

When was IH 45 NB Exit over Allen Parkway built?

It was built in 1955, making it 70 years old in 2025.

What condition is IH 45 NB Exit over Allen Parkway 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 NB Exit over Allen Parkway carry?

About 6,591 vehicles per day (2024 count), of which roughly 7% are trucks.

How long is IH 45 NB Exit over Allen Parkway?

The structure is 443 ft (135 m) long with a longest span of 63 ft (19.2 m) and a deck 25 ft wide.

Who owns IH 45 NB Exit over Allen Parkway?

It is owned by the State Highway Agency.