US Bridges

SH 121 NB Ramp a over Srt NB on Ramp B

Good

Collin County, Texas · 0.53 MI NE of Dnt · Structure no. 180430036404166

Built
2009
16 years old
Condition
Good
inspected November 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
400 ft
4 main spans
Daily traffic
21,000
2010 count
Owner
Toll Authority
Local Toll Authority

About this bridge

SH 121 NB Ramp a over Srt NB on Ramp B is a prestressed concrete stringer/multi-beam or girder carrying SH 121 NB Ramp a over Srt NB on Ramp B 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 21,000 vehicles a day, roughly 7% of them trucks, projected to reach 40,210 by 2030. The structure is 400 ft (121.9 m) long and 28 ft wide.

Location

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CarriesSH 121 NB Ramp a
CrossesSrt NB on Ramp B
Location0.53 MI NE of Dnt
CountyCollin County
StateTexas
Coordinates33.09443, -96.81063
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.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
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 loadHS 20
Structure length400 ft (121.9 m)
Longest span100 ft (30.5 m)
Deck width28 ft (8.5 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic21,000 (2010)
Projected traffic40,210 by 2030
Trucks7%
Lanes on structure1
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
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 Ramp a over Srt NB on Ramp B built?

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

What condition is SH 121 NB Ramp a over Srt NB on Ramp B 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 November 2023.

How much traffic does SH 121 NB Ramp a over Srt NB on Ramp B carry?

About 21,000 vehicles per day (2010 count), of which roughly 7% are trucks.

How long is SH 121 NB Ramp a over Srt NB on Ramp B?

The structure is 400 ft (121.9 m) long with a longest span of 100 ft (30.5 m) and a deck 28 ft wide.

Who owns SH 121 NB Ramp a over Srt NB on Ramp B?

It is owned by the Local Toll Authority.