Structure 16048900000000 · Cook County, IL

Il 171 NB First Av over Rr - Cn

Carries Il 171 NB First Av over Rr - Cn, 0.3 M SE I-55.

Overall conditionFair

Set by its lowest-rated component: Superstructure at 5 of 9.

How ratings work
Deck8/9 · Very Good
Superstructuresets the rating5/9 · Fair
Substructure7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT166 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 8/9Superstructure 5/9 · sets the ratingSubstructure 7/9

166 ft end to end, longest span 62 ft: about 2 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 multi-beam bridge.

Built1963rebuilt 2016
Length166.3 ft50.7 m
Daily traffic39,600counted 2023
Last inspectedJune 2023every 24 months

Location

StateIllinois
CountyCook
Location0.3 M SE I-55
CarriesIl 171 NB First Av
CrossesRr - Cn
Coordinates41.79145, -87.81569

Physical Characteristics

MaterialSteel Continuous
DesignStringer/Multi-beam
Total Length166.3 ft (50.7 m)
Max Span61.7 ft (18.8 m)
Deck Width56.1 ft (17.1 m)
Deck Area867.0 sq m
Main Spans3
Year Built1963 (reconstructed 2016)

Traffic

Avg Daily Traffic39,600 (2023)
Truck Traffic9%
Lanes On Bridge3

Inspection & Ownership

Last InspectionJune 2023
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure Number016048900000000

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.

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