US Bridges

407th Avenue over North Br Twelve Mile Ck

Poor

Davison County, South Dakota · 2 W & 10.2S Mitchell · Structure no. 000000018130202

Built
1930
95 years old
Condition
Poor
inspected August 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
35 ft
1 main span
Daily traffic
64
2022 count
Owner
County
County Highway Agency

About this bridge

407th Avenue over North Br Twelve Mile Ck is a steel stringer/multi-beam or girder carrying 407th Avenue over North Br Twelve Mile Ck in Davison County, South Dakota. It was built in 1930, so it is 95 years old, older than the South Dakota average of 48.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 64 vehicles a day, roughly 2% of them trucks, projected to reach 64 by 2032. The structure is 35 ft (10.7 m) long and 18 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Carries407th Avenue
CrossesNorth Br Twelve Mile Ck
Location2 W & 10.2S Mitchell
RouteCounty Highway 0
Coordinates43.55564, -98.06538
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating50.6 US tons
Inventory rating30.3 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length35 ft (10.7 m)
Longest span31 ft (9.4 m)
Deck width18 ft (5.5 m)
Roadway width18 ft (5.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic64 (2022)
Projected traffic64 by 2032
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

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

Frequently asked questions

When was 407th Avenue over North Br Twelve Mile Ck built?

It was built in 1930, making it 95 years old in 2025.

What condition is 407th Avenue over North Br Twelve Mile Ck in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in August 2024.

How much traffic does 407th Avenue over North Br Twelve Mile Ck carry?

About 64 vehicles per day (2022 count), of which roughly 2% are trucks.

How long is 407th Avenue over North Br Twelve Mile Ck?

The structure is 35 ft (10.7 m) long with a longest span of 31 ft (9.4 m) and a deck 18 ft wide.

Who owns 407th Avenue over North Br Twelve Mile Ck?

It is owned by the County Highway Agency.