Structure 85004A00.5013A · Montrose County, CO

County Road 4a over San Miguel River

Carries County Road 4a over San Miguel River, .2 Mi N Of CR 90.

Overall conditionFair

Set by its lowest-rated component: Deck and Substructure at 5 of 9.

How ratings work
Decksets the rating5/9 · Fair
Superstructure6/9 · Satisfactory
Substructuresets the rating5/9 · Fair
Channelnot part of overall6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT82 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 5/9 · sets the ratingSuperstructure 6/9Substructure 5/9 · sets the rating

82 ft end to end. Lengths and the car 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 multi-beam bridge.

Built198541 years old
Length82.0 ft25 m
Daily traffic586counted 2022
Last inspectedSeptember 2023every 24 months

Location

StateColorado
CountyMontrose
Location.2 Mi N Of CR 90
CarriesCounty Road 4a
CrossesSan Miguel River
Coordinates38.24070, -108.50717

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length82.0 ft (25 m)
Max Span78.4 ft (23.9 m)
Deck Width28.9 ft (8.8 m)
Deck Area220 sq m
Main Spans1
Year Built1985

Traffic

Avg Daily Traffic586 (2022)
Truck Traffic5%
Lanes On Bridge2

Inspection & Ownership

Last InspectionSeptember 2023
Inspection FrequencyEvery 24 months
OwnerCounty Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical5 — Stable for scour
Structure Number085004A00.5013A

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