US Bridges

I-81 Sb; SR 0081 over Twp RD 318; Kohn RD

Fair

Dauphin County, Pennsylvania · 1.5 Mi.N. Progress · Structure no. 000000000014225

Built
1969
56 years old
Condition
Fair
inspected October 2022
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
41 ft
1 main span
Daily traffic
45,173
2024 count
Owner
State
State Highway Agency

About this bridge

I-81 Sb; SR 0081 over Twp RD 318; Kohn RD is a prestressed concrete box beam or girders - multiple carrying I-81 Sb; SR 0081 over Twp RD 318; Kohn RD in Dauphin County, Pennsylvania. It was built in 1969, so it is 56 years old, older than the Pennsylvania average of 54.8 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 45,173 vehicles a day, roughly 22% of them trucks, projected to reach 53,865 by 2032. The structure is 41 ft (12.5 m) long and 55 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

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CarriesI-81 Sb; SR 0081
CrossesTwp RD 318; Kohn RD
Location1.5 Mi.N. Progress
RouteInterstate 81
CountyDauphin County
StatePennsylvania
Coordinates40.30183, -76.85742
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2022
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating78 US tons
Inventory rating48 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length41 ft (12.5 m)
Longest span37 ft (11.3 m)
Deck width55 ft (16.9 m)
Roadway width52 ft (15.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic45,173 (2024)
Projected traffic53,865 by 2032
Trucks22%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed6.8 mi (11 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 I-81 Sb; SR 0081 over Twp RD 318; Kohn RD built?

It was built in 1969, making it 56 years old in 2025.

What condition is I-81 Sb; SR 0081 over Twp RD 318; Kohn RD 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 October 2022.

How much traffic does I-81 Sb; SR 0081 over Twp RD 318; Kohn RD carry?

About 45,173 vehicles per day (2024 count), of which roughly 22% are trucks.

How long is I-81 Sb; SR 0081 over Twp RD 318; Kohn RD?

The structure is 41 ft (12.5 m) long with a longest span of 37 ft (11.3 m) and a deck 55 ft wide.

Who owns I-81 Sb; SR 0081 over Twp RD 318; Kohn RD?

It is owned by the State Highway Agency.