US Bridges

30th Street over Empson Ditch

Fair

Boulder County, Colorado · 0.59 MI N of Baseline RD · Structure no. BOLD-07-0.59-01

Built
1963
62 years old
Condition
Fair
inspected February 2025
Type
Tee Beam
Prestressed Concrete
Length
25 ft
1 main span
Daily traffic
16,733
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

30th Street over Empson Ditch is a prestressed concrete tee beam carrying 30th Street over Empson Ditch in Boulder County, Colorado. It was built in 1963, so it is 62 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 16,733 vehicles a day, roughly 2% of them trucks, projected to reach 20,080 by 2043. The structure is 25 ft (7.6 m) long and 62 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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Carries30th Street
CrossesEmpson Ditch
Location0.59 MI N of Baseline RD
RouteCity Street 0
CountyBoulder County
StateColorado
Coordinates40.00876, -105.25342
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating40 US tons
Inventory rating36 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadUnknown
Structure length25 ft (7.6 m)
Longest span22 ft (6.8 m)
Deck width62 ft (18.9 m)
Roadway width50 ft (15.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic16,733 (2023)
Projected traffic20,080 by 2043
Trucks2%
Lanes on structure4
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 proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$164,000 (2019 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was 30th Street over Empson Ditch built?

It was built in 1963, making it 62 years old in 2025.

What condition is 30th Street over Empson 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 30th Street over Empson Ditch carry?

About 16,733 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is 30th Street over Empson Ditch?

The structure is 25 ft (7.6 m) long with a longest span of 22 ft (6.8 m) and a deck 62 ft wide.

Who owns 30th Street over Empson Ditch?

It is owned by the City or Municipal Highway Agency.