Rock County, WI

325 public highway bridges

Rock County Bridge Snapshot

Rock County, Wisconsin contains 325 public highway bridges in the FHWA National Bridge Inventory. Roughly 36.9% are rated “Good,” 26.8% “Fair,” 3.4% “Poor,” and 3.4% are classified as structurally deficient — the federal designation for spans whose deck, superstructure, or substructure has been rated 4 or below on the 0–9 NBI scale. Structurally deficient does not mean unsafe to cross; it means the bridge is on the priority list for repair or replacement.

Inspections in WI are conducted by certified engineers from the state Department of Transportation on a 24-month cycle, and results are reported back to the FHWA each spring. The list below shows every NBI-tracked bridge in the county, sorted by inventory load rating. Use the “Sort by” controls to surface the lowest-rated spans first, and click any row for full inspection history, traffic counts, and condition trends.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

325

Total Bridges

36.9%

Good

3.4%

Poor

3.4%

Structurally Deficient

Condition Distribution

Good

36.9% (120)

Fair

26.8% (87)

Poor

3.4% (11)

SD

3.4% (11)

All Bridges (325)

Sort:

LRD E MEMORIAL DR

Over: USH 51-N PARKER DR

0.6M N JCT STH 26, Rock, WI

Built 1970 ADT: 15,900

IH 43 NB

Over: CTH X / HART RD

2.2M E JCT IH 90, Rock, WI

Built 1976 ADT: 3,300

IH 43 SB

Over: CTH X / HART RD

2.2M E JCT IH 90, Rock, WI

Built 1976 ADT: 3,300

IH 43 NB

Over: LRD SCHROEDER RD

0.5M N JCT CTH X, Rock, WI

Built 1975 ADT: 129

IH 43 SB

Over: LRD SCHROEDER RD

0.5M N JCT CTH X, Rock, WI

Built 1975 ADT: 129

IH 43 NB

Over: LRD BUSS RD

1.9M E JCT CTH J, Rock, WI

Built 1975 ADT: 533

IH 43 SB

Over: LRD BUSS RD

1.9M E JCT CTH J, Rock, WI

Built 1975 ADT: 533

IH 43 NB

Over: CTH J

1.3M N JCT CTH X, Rock, WI

Built 1975 ADT: 550

IH 43 NB

Over: STH 140

3.0M N JCT CTH P, Rock, WI

Built 1975 ADT: 4,400

IH 43 SB

Over: STH 140

3.1M N JCT CTH P, Rock, WI

Built 1975 ADT: 4,400

IH 43 NB

Over: LRD CARVERS ROCK RD

0.6M N JCT CTH X, Rock, WI

Built 1975 ADT: 176

IH 43 SB

Over: LRD CARVERS ROCK RD

0.6M N JCT CTH X, Rock, WI

Built 1975 ADT: 176

IH 43 NB

Over: LRD SUMMERVILLE RD

0.4M N JCT CTH X, Rock, WI

Built 1975 ADT: 147

IH 43 SB

Over: LRD SUMMERVILLE RD

0.4M N JCT CTH X, Rock, WI

Built 1975 ADT: 147

IH 43 SB

Over: CTH J

1.3M N JCT CTH X, Rock, WI

Built 1975 ADT: 550

LRD CROSBY - WILLA

Over: ROCK RIVER

AT CROSBY, Rock, WI

Built 1983 ADT: 99

LRD BLACK BRIDGE R

Over: LRD HAUL ROAD

CITY OF JANESVILLE, Rock, WI

Built 1983 ADT: 99

STH EB STH 11

Over: LRD READ RD

6.7M N JCT CTH S, Rock, WI

Built 1989 ADT: 429

USH 51

Over: CTH F

0.1M E JCT USH 14 TO E, Rock, WI

Built 1995 ADT: 641

STH 11

Over: LRD ROCKPORT RD

CITY OF JANESVILLE, Rock, WI

Built 2002 ADT: 99

CTH D

Over: STH 11

1.1M W OF JCT USH 51, Rock, WI

Built 2001 ADT: 99

STH EB STH 11

Over: LRD SOUTH RIVER ROAD

0.3M N OF JCT AVALON RD, Rock, WI

Built 2002 ADT: 99

STH WB STH 11

Over: LRD SOUTH RIVER ROAD

0.3M N OF JCT AVALON RD, Rock, WI

Built 2002 ADT: 1,500

STH EB STH 11

Over: LRD SOUTH OAKHILL AVE

0.1M N JCT W KNILANS RD, Rock, WI

Built 2002 ADT: 1,000

STH WB STH 11

Over: LRD SOUTH OAKHILL AVENUE

0.1M N JCT W KNILANS RD, Rock, WI

Built 2002 ADT: 99

IH 39 SB / IH 90 E

Over: LRD MILWAUKEE STREET

AT IH 90, Rock, WI

Built 2003 ADT: 8,600

IH 39 NB/ IH 90 WB

Over: LRD MILWAUKEE STREET

AT IH 90, Rock, WI

Built 2004 ADT: 8,600

IH 39 SB

Over: LRD COLLEY ROAD

AT IH 90, Rock, WI

Built 2003 ADT: 205

IH 39 NB/90 WB

Over: LRD COLLEY RD

AT IH90, Rock, WI

Built 2004 ADT: 205

STH 11 WB

Over: LRD S READ RD

AT STH11, Rock, WI

Built 2004 ADT: 150

LRD CRANSTON RD

Over: IH 90

0.7M E JCT IH 43, Rock, WI

Built 2003 ADT: 51,200

UNION PACIFIC RAIL

Over: LRD JACKSON STREET

AT UP RAILROAD, Rock, WI

Built 2004 ADT: 99

IH 39 SB / IH 90 E

Over: CTH O

AT IH 90, Rock, WI

Built 2003 ADT: 5,900

IH 39 NB/90 WB

Over: CTH O/ EAST DELAVAN ROAD

90, Rock, WI

Built 2004 ADT: 5,800

LRD HARMONY TOWN H

Over: STH 26

AT HARMONY TOWN HALL RD, Rock, WI

Built 2012 ADT: 17,500

LRD TOWNLINE ROAD

Over: STH 26

AT TOWNLINE ROAD, Rock, WI

Built 2012 ADT: 17,000

LRD HENKE RD

Over: STH 26 NB

AT HENKE RD, Rock, WI

Built 2013 ADT: 8,450

STH 26 NB

Over: STH 59

4.3 MI. N OF CTH Y, Rock, WI

Built 2013 ADT: 4,700

STH 26 SB

Over: STH 59

AT STH 26, Rock, WI

Built 2013 ADT: 4,700

STH 26 NB

Over: LRD E HIGH ST

0.4M E OF CTH M, Rock, WI

Built 2013 ADT: 750

STH 26 SB

Over: LRD E HIGH ST

0.4M E OF CTH M, Rock, WI

Built 2013 ADT: 750

STH 26 NB

Over: LRD STORRS LAKE ROAD

AT STH 26, Rock, WI

Built 2013 ADT: 100

STH 26 SB

Over: LRD STORRS LAKE RD

AT STH 26, Rock, WI

Built 2013 ADT: 100

STH 26 NB

Over: LRD BOWERS LAKE RD

AT STH 26, Rock, WI

Built 2013 ADT: 1,500

STH 26 SB

Over: LRD BOWERS LAKE RD

0.5M E OF N JANESVILLE ST, Rock, WI

Built 2013 ADT: 1,500

CTH N

Over: STH 26

AT CTH N, Rock, WI

Built 2012 ADT: 13,900

BIKE PATH

Over: STH 26

AT BIKE PATH, Rock, WI

Built 2012 ADT: 30,500

LRD WRIGHT RD

Over: STH 26

AT WRIGHT RD, Rock, WI

Built 2013 ADT: 18,000

IH 43 SB / STH 81

Over: IH 39 / IH 90

2.5M E JCT CTH S TO E, Rock, WI

Built 2021 ADT: 48,400

IH 43 NB / STH 81

Over: IH 39 / IH 90

2.5M E JCT CTH S TO E, Rock, WI

Built 2021 ADT: 48,400

Read our methodology — how this data is sourced, computed, and verified.

Related

Browse all → | Rankings →

Data sourced from official U.S. government datasets. See our methodology for details. Retrieved and formatted by PlainBridges Editorial

Reviewed byPlainbridges Editorial, Plain Bridges Editorial Team · June 5, 2026