US Bridges

SR91 N/S Tpk 138.1 over County Line Canal C-23

Fair

Martin County, Florida · 3.4MI North of SR-714 · Structure no. 890083

Built
1957
68 years old, rebuilt 2007
Condition
Fair
inspected December 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
327 ft
7 main spans
Daily traffic
59,900
2023 count
Owner
Toll Authority
State Toll Authority

About this bridge

SR91 N/S Tpk 138.1 over County Line Canal C-23 is a steel stringer/multi-beam or girder carrying SR91 N/S Tpk 138.1 over County Line Canal C-23 in Martin County, Florida. It was built in 1957 and reconstructed in 2007, so it is 68 years old, older than the Florida average of 41.3 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 59,900 vehicles a day, roughly 20% of them trucks, projected to reach 103,926 by 2042. The structure is 327 ft (99.7 m) long and 103 ft wide. If it were closed, the detour would be 9.3 mi (15 km).

Location

Open in Google Maps
CarriesSR91 N/S Tpk 138.1
CrossesCounty Line Canal C-23
Location3.4MI North of SR-714
RouteState Highway 91
CountyMartin County
StateFlorida
Coordinates27.20555, -80.33175
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 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 geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating61.6 US tons
Inventory rating36.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans7
Design loadHS 20
Structure length327 ft (99.7 m)
Longest span47 ft (14.4 m)
Deck width103 ft (31.4 m)
Roadway width98 ft (29.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic59,900 (2023)
Projected traffic103,926 by 2042
Trucks20%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway
CrossesRelief for waterway
Detour if closed9.3 mi (15 km)
TollOn a toll road
National Highway SystemYes

Ownership and planned work

OwnerState Toll Authority
Maintained byState 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 SR91 N/S Tpk 138.1 over County Line Canal C-23 built?

It was built in 1957, making it 68 years old in 2025. It was reconstructed in 2007.

What condition is SR91 N/S Tpk 138.1 over County Line Canal C-23 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 December 2023.

How much traffic does SR91 N/S Tpk 138.1 over County Line Canal C-23 carry?

About 59,900 vehicles per day (2023 count), of which roughly 20% are trucks.

How long is SR91 N/S Tpk 138.1 over County Line Canal C-23?

The structure is 327 ft (99.7 m) long with a longest span of 47 ft (14.4 m) and a deck 103 ft wide.

Who owns SR91 N/S Tpk 138.1 over County Line Canal C-23?

It is owned by the State Toll Authority.