US Bridges

Lookout Road over Whiterock Ditch

Fair

Boulder County, Colorado · 0.32 MI E of Spine Street · Structure no. BOLD-17-0.32-2A

Built
1996
29 years old
Condition
Fair
inspected January 2025
Type
Culvert
Concrete
Length
21 ft
1 main span
Daily traffic
10,395
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Lookout Road over Whiterock Ditch is a concrete culvert carrying Lookout Road over Whiterock Ditch 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 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 10,395 vehicles a day, roughly 4% of them trucks, projected to reach 12,474 by 2043. The structure is 21 ft (6.4 m) long and 78 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesLookout Road
CrossesWhiterock Ditch
Location0.32 MI E of Spine Street
RouteCity Street 0
CountyBoulder County
StateColorado
Coordinates40.07269, -105.19626
Functional classUrban Minor 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.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating110.1 US tons
Inventory rating110.1 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans1
Design loadHS 20
Structure length21 ft (6.4 m)
Longest span21 ft (6.4 m)
Deck width78 ft (23.9 m)
Roadway width36 ft (11 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,395 (2023)
Projected traffic12,474 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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 Lookout Road over Whiterock Ditch built?

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

What condition is Lookout Road over Whiterock Ditch 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 2025.

How much traffic does Lookout Road over Whiterock Ditch carry?

About 10,395 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Lookout Road over Whiterock Ditch?

The structure is 21 ft (6.4 m) long with a longest span of 21 ft (6.4 m) and a deck 78 ft wide.

Who owns Lookout Road over Whiterock Ditch?

It is owned by the City or Municipal Highway Agency.