US Bridges

Old Mamalahoa HWY over Keaakaukau Gulch

Fair

Hawaii County, Hawaii · Tmk: 4-6-009:035 · Structure no. 001460001100004

Built
1925
100 years old
Condition
Fair
inspected August 2024
Type
Slab
Concrete Continuous
Length
24 ft
2 main spans
Daily traffic
600
1981 count
Owner
County
County Highway Agency

About this bridge

Old Mamalahoa HWY over Keaakaukau Gulch is a concrete continuous slab carrying Old Mamalahoa HWY over Keaakaukau Gulch in Hawaii County, Hawaii. It was built in 1925, so it is 100 years old, older than the Hawaii average of 63.8 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 600 vehicles a day, projected to reach 750 by 2025. The structure is 24 ft (7.3 m) long and 20 ft wide. If it were closed, the detour would be 16.2 mi (26 km).

Location

Open in Google Maps
CarriesOld Mamalahoa HWY
CrossesKeaakaukau Gulch
LocationTmk: 4-6-009:035
RouteCounty Highway 0
CountyHawaii County
StateHawaii
Coordinates20.05493, -155.50672
Functional classRural Local

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating41.4 US tons
Inventory rating32.2 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadUnknown
Structure length24 ft (7.3 m)
Longest span12 ft (3.7 m)
Deck width20 ft (6.1 m)
Roadway width18 ft (5.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic600 (1981)
Projected traffic750 by 2025
Trucks0%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed16.2 mi (26 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$136,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Old Mamalahoa HWY over Keaakaukau Gulch built?

It was built in 1925, making it 100 years old in 2025.

What condition is Old Mamalahoa HWY over Keaakaukau Gulch 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 August 2024.

How much traffic does Old Mamalahoa HWY over Keaakaukau Gulch carry?

About 600 vehicles per day (1981 count).

How long is Old Mamalahoa HWY over Keaakaukau Gulch?

The structure is 24 ft (7.3 m) long with a longest span of 12 ft (3.7 m) and a deck 20 ft wide.

Who owns Old Mamalahoa HWY over Keaakaukau Gulch?

It is owned by the County Highway Agency.