US Bridges

Algonquin Road over Crystal Creek

Fair

McHenry County, Illinois · 02M W of Pyott · Structure no. 056316500000000

Built
2004
21 years old
Condition
Fair
inspected October 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
60 ft
1 main span
Daily traffic
31,600
2023 count
Owner
County
County Highway Agency

About this bridge

Algonquin Road over Crystal Creek is a prestressed concrete box beam or girders - multiple carrying Algonquin Road over Crystal Creek in McHenry County, Illinois. It was built in 2004, so it is 21 years old, younger than the Illinois average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 31,600 vehicles a day, roughly 3% of them trucks, projected to reach 36,960 by 2046. The structure is 60 ft (18.4 m) long and 65 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesAlgonquin Road
CrossesCrystal Creek
Location02M W of Pyott
CountyMcHenry County
StateIllinois
Coordinates42.17603, -88.30775
Functional classUrban Other Principal Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating66.8 US tons
Inventory rating40 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length60 ft (18.4 m)
Longest span56 ft (17 m)
Deck width65 ft (19.8 m)
Roadway width58 ft (17.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic31,600 (2023)
Projected traffic36,960 by 2046
Trucks3%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Algonquin Road over Crystal Creek built?

It was built in 2004, making it 21 years old in 2025.

What condition is Algonquin Road over Crystal Creek in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in October 2024.

How much traffic does Algonquin Road over Crystal Creek carry?

About 31,600 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Algonquin Road over Crystal Creek?

The structure is 60 ft (18.4 m) long with a longest span of 56 ft (17 m) and a deck 65 ft wide.

Who owns Algonquin Road over Crystal Creek?

It is owned by the County Highway Agency.