US Bridges

SH 121 Sbml over Sister Grove Creek

Good

Collin County, Texas · 5.85 MI NE of FM 545 · Structure no. 180430054903237

Built
2020
5 years old
Condition
Good
inspected August 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
1,270 ft
14 main spans
Daily traffic
6,400
2016 count
Owner
State
State Highway Agency

About this bridge

SH 121 Sbml over Sister Grove Creek is a prestressed concrete stringer/multi-beam or girder carrying SH 121 Sbml over Sister Grove Creek in Collin 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 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 6,400 vehicles a day, roughly 6% of them trucks, projected to reach 1 by 1900. The structure is 1,270 ft (387.1 m) long and 40 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesSH 121 Sbml
CrossesSister Grove Creek
Location5.85 MI NE of FM 545
RouteState Highway 121
CountyCollin County
StateTexas
Coordinates33.33308, -96.48067
Functional classUrban Other Principal Arterial

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 inspectionAugust 2023
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 adequacy8: Equal to present desirable 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 spans14
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 traffic6,400 (2016)
Projected traffic1 by 1900
Trucks6%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and waterway
Detour if closed5 mi (8 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 Sbml over Sister Grove Creek built?

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

What condition is SH 121 Sbml over Sister Grove Creek 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 2023.

How much traffic does SH 121 Sbml over Sister Grove Creek carry?

About 6,400 vehicles per day (2016 count), of which roughly 6% are trucks.

How long is SH 121 Sbml over Sister Grove Creek?

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 Sbml over Sister Grove Creek?

It is owned by the State Highway Agency.