US Bridges

SH 121 Nbml over Sister Grove Crk/Fm 455

Good

Collin County, Texas · 5.85 MI NE of FM 545 · Structure no. 180430054903236

Built
2022
3 years old
Condition
Good
inspected April 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
1,270 ft
10 main spans
Daily traffic
15,069
2020 count
Owner
State
State Highway Agency

About this bridge

SH 121 Nbml over Sister Grove Crk/Fm 455 is a prestressed concrete stringer/multi-beam or girder carrying SH 121 Nbml over Sister Grove Crk/Fm 455 in Collin County, Texas. It was built in 2022, so it is 3 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 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 15,069 vehicles a day, roughly 10% of them trucks, projected to reach 22,905 by 2040. The structure is 1,270 ft (387.1 m) long and 40 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesSH 121 Nbml
CrossesSister Grove Crk/Fm 455
Location5.85 MI NE of FM 545
RouteState Highway 121
StateTexas
Coordinates33.33749, -96.47369
Functional classRural Principal Arterial - Other

Condition and inspection

Good

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy9: Superior to present desirable 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 spans10 (+4 approach)
Design loadHL 93
Structure length1,270 ft (387.1 m)
Longest span105 ft (32 m)
Deck width40 ft (12.2 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic15,069 (2020)
Projected traffic22,905 by 2040
Trucks10%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and waterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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—
NavigationNo navigation control on waterway

Frequently asked questions

When was SH 121 Nbml over Sister Grove Crk/Fm 455 built?

It was built in 2022, making it 3 years old in 2025.

What condition is SH 121 Nbml over Sister Grove Crk/Fm 455 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 April 2024.

How much traffic does SH 121 Nbml over Sister Grove Crk/Fm 455 carry?

About 15,069 vehicles per day (2020 count), of which roughly 10% are trucks.

How long is SH 121 Nbml over Sister Grove Crk/Fm 455?

The structure is 1,270 ft (387.1 m) long with a longest span of 105 ft (32 m) and a deck 40 ft wide.

Who owns SH 121 Nbml over Sister Grove Crk/Fm 455?

It is owned by the State Highway Agency.