US Bridges

Spur 408 NB over Grady Niblo RD

Fair

Dallas County, Texas · 1.4 MI N of IH 20 · Structure no. 180570300001005

Built
1975
50 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
256 ft
4 main spans
Daily traffic
50,243
2023 count
Owner
State
State Highway Agency

About this bridge

Spur 408 NB over Grady Niblo RD is a prestressed concrete stringer/multi-beam or girder carrying Spur 408 NB over Grady Niblo RD in Dallas County, Texas. It was built in 1975, so it is 50 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 6 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 50,243 vehicles a day, roughly 9% of them trucks, projected to reach 134,382 by 2040. The structure is 256 ft (78 m) long and 62 ft wide.

CarriesSpur 408 NB
CrossesGrady Niblo RD
Location1.4 MI N of IH 20
RouteState Highway 408
StateTexas
Coordinates32.69106, -96.93834
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum 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

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length256 ft (78 m)
Longest span70 ft (21.3 m)
Deck width62 ft (18.9 m)
Roadway width60 ft (18.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50,243 (2023)
Projected traffic134,382 by 2040
Trucks9%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
TollOn a free road
National Highway SystemYes

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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Spur 408 NB over Grady Niblo RD built?

It was built in 1975, making it 50 years old in 2025.

What condition is Spur 408 NB over Grady Niblo RD 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 October 2023.

How much traffic does Spur 408 NB over Grady Niblo RD carry?

About 50,243 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is Spur 408 NB over Grady Niblo RD?

The structure is 256 ft (78 m) long with a longest span of 70 ft (21.3 m) and a deck 62 ft wide.

Who owns Spur 408 NB over Grady Niblo RD?

It is owned by the State Highway Agency.