US Bridges

I0055 over I-55 Off Ramp @ US 51

Good

St. John the Baptist Parish, Louisiana · 0.1 M N of US 51 · Structure no. 624804520100908

Built
1975
50 years old
Condition
Good
inspected June 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
675 ft
10 main spans
Daily traffic
15,642
2021 count
Owner
State
State Highway Agency

About this bridge

I0055 over I-55 Off Ramp @ US 51 is a prestressed concrete stringer/multi-beam or girder carrying I0055 over I-55 Off Ramp @ US 51 in St. John the Baptist Parish, Louisiana. It was built in 1975, so it is 50 years old, older than the Louisiana average of 43 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 15,642 vehicles a day, roughly 26% of them trucks, projected to reach 17,206 by 2041. The structure is 675 ft (205.7 m) long and 28 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesI0055
CrossesI-55 Off Ramp @ US 51
Location0.1 M N of US 51
RouteInterstate 55
CountySt. John the Baptist Parish
StateLouisiana
Coordinates30.09481, -90.439
Functional classUrban Principal Arterial - Interstate

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 protection8 Very GoodNo problems noted.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
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 rating99 US tons
Inventory rating39 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans10 (+3 approach)
Design loadHS 20
Structure length675 ft (205.7 m)
Longest span60 ft (18.3 m)
Deck width28 ft (8.5 m)
Roadway width25 ft (7.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic15,642 (2021)
Projected traffic17,206 by 2041
Trucks26%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway
CrossesRelief for waterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I0055 over I-55 Off Ramp @ US 51 built?

It was built in 1975, making it 50 years old in 2025.

What condition is I0055 over I-55 Off Ramp @ US 51 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 June 2023.

How much traffic does I0055 over I-55 Off Ramp @ US 51 carry?

About 15,642 vehicles per day (2021 count), of which roughly 26% are trucks.

How long is I0055 over I-55 Off Ramp @ US 51?

The structure is 675 ft (205.7 m) long with a longest span of 60 ft (18.3 m) and a deck 28 ft wide.

Who owns I0055 over I-55 Off Ramp @ US 51?

It is owned by the State Highway Agency.