US Bridges

IH 45 Nbml over FM 646

Good

Galveston County, Texas · 1.40 MI NW of FM 517 · Structure no. 120850050004453

Built
2020
5 years old
Condition
Good
inspected August 2022
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
350 ft
3 main spans
Daily traffic
115,900
2016 count
Owner
State
State Highway Agency

About this bridge

IH 45 Nbml over FM 646 is a prestressed concrete stringer/multi-beam or girder carrying IH 45 Nbml over FM 646 in Galveston County, Texas. It was built in 2020, so it is 5 years old, younger than the Texas average of 44.4 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 115,900 vehicles a day, roughly 4% of them trucks, projected to reach 159,700 by 2036. The structure is 350 ft (106.7 m) long and 85 ft wide.

Location

Open in Google Maps
CarriesIH 45 Nbml
CrossesFM 646
Location1.40 MI NW of FM 517
RouteInterstate 45
CountyGalveston County
StateTexas
Coordinates29.46606, -95.09063
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Last inspectionAugust 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation8: Equal to present desirable criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating60 US tons
Inventory rating36 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length350 ft (106.7 m)
Longest span124 ft (37.8 m)
Deck width85 ft (25.9 m)
Roadway width84 ft (25.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic115,900 (2016)
Projected traffic159,700 by 2036
Trucks4%
Lanes on structure5
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was IH 45 Nbml over FM 646 built?

It was built in 2020, making it 5 years old in 2025.

What condition is IH 45 Nbml over FM 646 in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in August 2022.

How much traffic does IH 45 Nbml over FM 646 carry?

About 115,900 vehicles per day (2016 count), of which roughly 4% are trucks.

How long is IH 45 Nbml over FM 646?

The structure is 350 ft (106.7 m) long with a longest span of 124 ft (37.8 m) and a deck 85 ft wide.

Who owns IH 45 Nbml over FM 646?

It is owned by the State Highway Agency.