US Bridges

County RD 420 over Portage Byu

Good

New Madrid County, Missouri · S 14 T 21 N R 13 E · Structure no. 32156

Built
2005
20 years old
Condition
Good
inspected December 2024
Type
Channel Beam
Concrete Continuous
Length
66 ft
3 main spans
Daily traffic
5
2023 count
Owner
County
County Highway Agency

About this bridge

County RD 420 over Portage Byu is a concrete continuous channel beam carrying County RD 420 over Portage Byu in New Madrid County, Missouri. It was built in 2005, so it is 20 years old, younger than the Missouri average of 45.1 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 5 vehicles a day, roughly 10% of them trucks, projected to reach 7 by 2043. The structure is 66 ft (20.2 m) long and 25 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesCounty RD 420
CrossesPortage Byu
LocationS 14 T 21 N R 13 E
RouteCounty Highway 420
CountyNew Madrid County
StateMissouri
Coordinates36.46182, -89.61377
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure7 GoodSome minor problems.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating110.1 US tons
Inventory rating93.3 US tons

Structure

Structure typeChannel Beam
MaterialConcrete Continuous
DeckConcrete, precast panels
Main spans3
Design loadHS 20
Structure length66 ft (20.2 m)
Longest span22 ft (6.7 m)
Deck width25 ft (7.5 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5 (2023)
Projected traffic7 by 2043
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was County RD 420 over Portage Byu built?

It was built in 2005, making it 20 years old in 2025.

What condition is County RD 420 over Portage Byu in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in December 2024.

How much traffic does County RD 420 over Portage Byu carry?

About 5 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is County RD 420 over Portage Byu?

The structure is 66 ft (20.2 m) long with a longest span of 22 ft (6.7 m) and a deck 25 ft wide.

Who owns County RD 420 over Portage Byu?

It is owned by the County Highway Agency.