Structure F-15-AE · Jefferson County, CO

Lookout Mountain R over I 70 Ml

Carries Lookout Mountain R over I 70 Ml, 4.3 Mi E Of Jct SH 74.

Overall conditionPoor

Set by its lowest-rated component: Superstructure at 4 of 9.

How ratings work
Deck5/9 · Fair
Superstructuresets the rating4/9 · Poor
Substructure6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT237 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 5/9Superstructure 4/9 · sets the ratingSubstructure 6/9

237 ft end to end, longest span 120 ft: about 3 semi-trucks nose to tail. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a box-beam bridge.

Built197056 years old
Length236.5 ft72.1 m
Daily traffic6,252counted 2024
Last inspectedFebruary 2024every 24 months

Location

StateColorado
CountyJefferson
Location4.3 Mi E Of Jct SH 74
CarriesLookout Mountain R
CrossesI 70 Ml
Coordinates39.70359, -105.25079

Physical Characteristics

MaterialConcrete Continuous
DesignBox Beam - Single/Spread
Total Length236.5 ft (72.1 m)
Max Span120.1 ft (36.6 m)
Deck Width46.6 ft (14.2 m)
Deck Area1023.8 sq m
Main Spans2
Year Built1970

Traffic

Avg Daily Traffic6,252 (2024)
Truck Traffic3%
Lanes On Bridge2
Lanes Under Bridge6

Inspection & Ownership

Last InspectionFebruary 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure NumberF-15-AE

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

Nearby Bridges