US Bridges

Mamalahoa over Naalehu Rdd Cnt

Good

Hawaii County, Hawaii · Tmk 9-5-21:21 · Structure no. 001950001100003

Built
1966
59 years old
Condition
Good
inspected February 2023
Type
Slab
Concrete
Length
22 ft
1 main span
Daily traffic
3,730
2019 count
Owner
State
State Highway Agency

About this bridge

Mamalahoa over Naalehu Rdd Cnt is a concrete slab carrying Mamalahoa over Naalehu Rdd Cnt in Hawaii County, Hawaii. It was built in 1966, so it is 59 years old, younger than the Hawaii average of 63.8 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 3,730 vehicles a day, projected to reach 3,550 by 2027. The structure is 22 ft (6.7 m) long and 40 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesMamalahoa
CrossesNaalehu Rdd Cnt
LocationTmk 9-5-21:21
RouteU.S. Route 11
CountyHawaii County
StateHawaii
Coordinates19.061, -155.584
Functional classRural Minor Arterial

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionFebruary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating42.5 US tons
Inventory rating32.8 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length22 ft (6.7 m)
Longest span20 ft (6.1 m)
Deck width40 ft (12.2 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,730 (2019)
Projected traffic3,550 by 2027
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$195,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Mamalahoa over Naalehu Rdd Cnt built?

It was built in 1966, making it 59 years old in 2025.

What condition is Mamalahoa over Naalehu Rdd Cnt 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 February 2023.

How much traffic does Mamalahoa over Naalehu Rdd Cnt carry?

About 3,730 vehicles per day (2019 count).

How long is Mamalahoa over Naalehu Rdd Cnt?

The structure is 22 ft (6.7 m) long with a longest span of 20 ft (6.1 m) and a deck 40 ft wide.

Who owns Mamalahoa over Naalehu Rdd Cnt?

It is owned by the State Highway Agency.