US Bridges

South Boulder RD over Drainage Ditch Ar

Fair

Boulder County, Colorado · In Lafayette · Structure no. E-16-PO

Built
1996
29 years old
Condition
Fair
inspected January 2024
Type
Culvert
Concrete
Length
20 ft
1 main span
Daily traffic
37,000
2021 count
Owner
State
State Highway Agency

About this bridge

South Boulder RD over Drainage Ditch Ar is a concrete culvert carrying South Boulder RD over Drainage Ditch Ar in Boulder County, Colorado. It was built in 1996, so it is 29 years old, younger than the Colorado average of 42.2 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 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 37,000 vehicles a day, roughly 4% of them trucks, projected to reach 44,400 by 2041. The structure is 20 ft (6.1 m) long and 194 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

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CarriesSouth Boulder RD
CrossesDrainage Ditch Ar
LocationIn Lafayette
RouteU.S. Route 287C
CountyBoulder County
StateColorado
Coordinates39.98681, -105.09884
Functional classUrban Other Principal Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Channel and channel protection7 GoodSome minor problems.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJanuary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating40 US tons
Inventory rating36 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans1
Design loadHS 20
Structure length20 ft (6.1 m)
Longest span20 ft (6.1 m)
Deck width194 ft (59.1 m)
Roadway width96 ft (29.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic37,000 (2021)
Projected traffic44,400 by 2041
Trucks4%
Lanes on structure8
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed0.6 mi (1 km)
TollOn a free road
National Highway SystemYes

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—
NavigationNo navigation control on waterway

Frequently asked questions

When was South Boulder RD over Drainage Ditch Ar built?

It was built in 1996, making it 29 years old in 2025.

What condition is South Boulder RD over Drainage Ditch Ar 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 January 2024.

How much traffic does South Boulder RD over Drainage Ditch Ar carry?

About 37,000 vehicles per day (2021 count), of which roughly 4% are trucks.

How long is South Boulder RD over Drainage Ditch Ar?

The structure is 20 ft (6.1 m) long with a longest span of 20 ft (6.1 m) and a deck 194 ft wide.

Who owns South Boulder RD over Drainage Ditch Ar?

It is owned by the State Highway Agency.