BridgeReport.org / States / Wisconsin

Wisconsin Bridges

14,446 highway bridges across 72 counties · NBI 2024 data

6.5% in poor condition
National avg: 6.8%
7,368
6,136
942
Good: 7,368 (51.0%) Fair: 6,136 (42.5%) Poor: 942 (6.5%)

About Wisconsin's Bridge Infrastructure

Wisconsin maintains 14,446 highway bridges across 72 counties, forming critical links in the state's transportation network. With an average construction year of 1984, the typical bridge in Wisconsin is approximately 42 years old—7 years newer than the national average of 49 years. The state's oldest bridge dates back to 1887, representing over a century of service and offering a window into historic bridge engineering practices.

Currently, 6.5% of Wisconsin's bridges are rated in poor condition, better than the national average of 6.8%. This indicates relatively strong investment in bridge maintenance and replacement programs. A "poor" condition rating indicates significant deterioration requiring attention, though these bridges remain safe for travel at their posted limits. Federal regulations require bridge inspections at least every 24 months to ensure public safety.

Bridge conditions in Wisconsin reflect decades of infrastructure investment decisions shaped by geography, climate, traffic demands, and available funding. Average daily traffic of 5,527 vehicles per bridge is below the national average, which can reduce wear but still requires consistent maintenance investment. The state's 79,829,028 total daily bridge crossings underscore how essential this infrastructure is to daily commerce and commuting.

The material composition of Wisconsin's bridge inventory reflects regional construction practices and evolving engineering standards. The predominant construction material is concrete, accounting for 43.8% of all structures. Material choice affects maintenance requirements, expected lifespan, and vulnerability to environmental factors specific to the region. Understanding these patterns helps transportation planners allocate resources effectively and prioritize infrastructure investments.

942 of 14,446 Wisconsin bridges have a rating of 4 or below. Rating 4 = advanced deterioration.

#BridgeRatingLocationBuiltDaily Traffic
1LRD CASBERG COULEE
over LONG COULEE CREEK
Critical condition requiring immediate attention.
0
La Crosse County Co. · 0.2M E JCT CTH V1984265
2LRD 25TH AVENUE
over SWAN CREEK
Critical condition requiring immediate attention. Low-traffic rural crossing.
0
Chippewa County Co. · 0.35 M E 350TH STREET200265
3LRD MILL ST
over UNION PACIFIC RR
Critical condition requiring immediate attention. At 126 years old, this is among Wisconsin's oldest structures. Low-traffic rural crossing.
0
Columbia County Co. · 0.1M W JCT STH 60190079
4LRD SOPER RD (CLOS
over N BR OCONTO RIVER
Critical condition requiring immediate attention. At 109 years old, this is among Wisconsin's oldest structures.
0
Forest County Co. · 0.5M E JCT STH 321917
5LRD TOWN PARK DR (
over W BR MONTREAL RIVER
Critical condition requiring immediate attention. Built 69 years ago, approaching the end of typical service life. Low-traffic rural crossing.
0
Iron County Co. · 0.6M S JCT USH 219571
6LRD 14TH RD
over CNW RR
Critical condition requiring immediate attention. At 86 years old, this is among Wisconsin's oldest structures. Low-traffic rural crossing.
0
Marquette County Co. · 0.7M S JCT CTH F194095
7LRD N 50TH ST (DEA
over MENOMONEE RIVER
Critical condition requiring immediate attention. Low-traffic rural crossing.
0
Milwaukee County Co. · 0.2M S JCT STATE ST19761
8LRD LATHERS RD
over TURTLE CREEK
Critical condition requiring immediate attention. At 139 years old, this is among Wisconsin's oldest structures.
0
Rock County Co. · 0.1M N JCT CTH S1887474
9LRD SCHOOL HOUSE R
over N BR EMBARRASS RIVER
Critical condition requiring immediate attention. At 106 years old, this is among Wisconsin's oldest structures.
0
Shawano County Co. · 1.7 M E JCT CTH D1920120
10LRD PEDESTRIAN (WO
over MILWAUKEE RIVER
Critical condition requiring immediate attention. At 135 years old, this is among Wisconsin's oldest structures.
0
Washington County Co. · 0.5M E JCT USH 451891

Bridges by County

Milwaukee County holds 6% of Wisconsin's bridges. Clark County has the highest deficiency rate.

CountyBridgesConditionPoorPoor %Avg ADT
Milwaukee County
Largest bridge inventory in Wisconsin. High-traffic area averaging 21,637 vehicles per bridge daily.
893
455
380
45
455.0%21,637
Dane County
One of Wisconsin's largest bridge inventories.
590
301
251
38
386.4%14,239
Marathon County
One of Wisconsin's largest bridge inventories. Poor condition rate significantly above state average.
530
270
225
54
5410.2%4,248
Brown County466
238
198
183.9%14,682
Grant County383
195
163
174.4%910
Monroe County374
191
159
133.5%3,214
Waukesha County369
188
157
24
246.5%12,898
Chippewa County359
183
153
33
339.2%2,890
Vernon County333
170
142
25
257.5%584
Barron County319
163
136
18
185.6%1,569

Infrastructure Profile

Key Metrics
Average bridge age42 years
Average year built1984
Oldest bridge1887
Newest bridge2023
Avg daily traffic/bridge5,527
Total daily crossings79.8M
Rating Distribution (0–9 scale)
0–4 = Poor · 5–6 = Fair · 7–9 = Good
Construction Materials
Concrete6,321(43.8%)
Prestressed Concrete4,506(31.2%)
Steel2,969(20.6%)
Wood/Timber555(3.8%)
Metal (Other)80(0.6%)
Masonry15(0.1%)

Wisconsin vs. National Average

Poor Condition
6.5%
National: 6.8%✓ Better
Good Condition
51.0%
National: 44.1%✓ Better
Average Age
42 yr
National: 49 yr✓ Better
Avg Daily Traffic
5,527
National: 7,954✓ Better
Data Source: Federal Highway Administration, National Bridge Inventory 2024. Bridge conditions rated 0–9 per FHWA Recording and Coding Guide. "Poor" = rating ≤ 4 on deck, superstructure, substructure, or culvert.
Inspections typically occur every 24 months. Structurally deficient does not mean unsafe.
Wisconsin Bridges — 14,446 Bridges, 6.5% Poor | BridgeReport.org