US Bridges

SH 121 NB over Alma Drive

Good

Collin County, Texas · 1.6 MI NE of FM 2478 · Structure no. 180430036404440

Built
2009
16 years old
Condition
Good
inspected December 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
330 ft
4 main spans
Daily traffic
22,796
2018 count
Owner
Toll Authority
Local Toll Authority

About this bridge

SH 121 NB over Alma Drive is a prestressed concrete stringer/multi-beam or girder carrying SH 121 NB over Alma Drive in Collin County, Texas. It was built in 2009, so it is 16 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 22,796 vehicles a day, roughly 6% of them trucks, projected to reach 31,915 by 2038. The structure is 330 ft (100.6 m) long and 70 ft wide.

Location

Open in Google Maps
CarriesSH 121 NB
CrossesAlma Drive
Location1.6 MI NE of FM 2478
CountyCollin County
StateTexas
Coordinates33.13409, -96.70689
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to 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 spans4
Design loadHL 93
Structure length330 ft (100.6 m)
Longest span90 ft (27.4 m)
Deck width70 ft (21.3 m)
Roadway width68 ft (20.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic22,796 (2018)
Projected traffic31,915 by 2038
Trucks6%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
TollOn a toll road
National Highway SystemYes

Ownership and planned work

OwnerLocal Toll Authority
Maintained byLocal Toll Authority
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 NB over Alma Drive built?

It was built in 2009, making it 16 years old in 2025.

What condition is SH 121 NB over Alma Drive 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 December 2023.

How much traffic does SH 121 NB over Alma Drive carry?

About 22,796 vehicles per day (2018 count), of which roughly 6% are trucks.

How long is SH 121 NB over Alma Drive?

The structure is 330 ft (100.6 m) long with a longest span of 90 ft (27.4 m) and a deck 70 ft wide.

Who owns SH 121 NB over Alma Drive?

It is owned by the Local Toll Authority.