US Bridges

Sterling Drive over Left Hand Ditch

Fair

Boulder County, Colorado · 100 Ft E of 47th Street · Structure no. BOLD-33-STERDR

Built
1975
50 years old
Condition
Fair
inspected February 2025
Type
Culvert
Concrete
Length
20 ft
2 main spans
Daily traffic
937
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Sterling Drive over Left Hand Ditch is a concrete culvert carrying Sterling Drive over Left Hand Ditch in Boulder County, Colorado. It was built in 1975, so it is 50 years old, older 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 937 vehicles a day, roughly 13% of them trucks, projected to reach 1,125 by 2042. The structure is 20 ft (6.1 m) long and 55 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSterling Drive
CrossesLeft Hand Ditch
Location100 Ft E of 47th Street
RouteCity Street 0
CountyBoulder County
StateColorado
Coordinates40.02725, -105.24379
Functional classUrban 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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating40 US tons
Inventory rating36 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans2
Design loadHS 20
Structure length20 ft (6.1 m)
Longest span10 ft (2.9 m)
Deck width55 ft (16.7 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic937 (2023)
Projected traffic1,125 by 2042
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Sterling Drive over Left Hand Ditch built?

It was built in 1975, making it 50 years old in 2025.

What condition is Sterling Drive over Left Hand 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 February 2025.

How much traffic does Sterling Drive over Left Hand Ditch carry?

About 937 vehicles per day (2023 count), of which roughly 13% are trucks.

How long is Sterling Drive over Left Hand Ditch?

The structure is 20 ft (6.1 m) long with a longest span of 10 ft (2.9 m) and a deck 55 ft wide.

Who owns Sterling Drive over Left Hand Ditch?

It is owned by the City or Municipal Highway Agency.