US Bridges

US 20 over C and NW Railroad

Fair

Natrona County, Wyoming · Casper · Structure no. DDG

Built
1977
48 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
270 ft
3 main spans
Daily traffic
11,584
2024 count
Owner
State
State Highway Agency

About this bridge

US 20 over C and NW Railroad is a steel continuous stringer/multi-beam or girder carrying US 20 over C and NW Railroad in Natrona County, Wyoming. It was built in 1977, so it is 48 years old, younger than the Wyoming average of 48.4 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 11,584 vehicles a day, roughly 4% of them trucks, projected to reach 16,218 by 2043. The structure is 270 ft (82.3 m) long and 87 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesUS 20
CrossesC and NW Railroad
LocationCasper
RouteU.S. Route 20
CountyNatrona County
StateWyoming
Coordinates42.84669, -106.36721
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating69 US tons
Inventory rating40 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length270 ft (82.3 m)
Longest span104 ft (31.7 m)
Deck width87 ft (26.6 m)
Roadway width78 ft (23.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11,584 (2024)
Projected traffic16,218 by 2043
Trucks4%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesRailroad
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was US 20 over C and NW Railroad built?

It was built in 1977, making it 48 years old in 2025.

What condition is US 20 over C and NW Railroad 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 April 2024.

How much traffic does US 20 over C and NW Railroad carry?

About 11,584 vehicles per day (2024 count), of which roughly 4% are trucks.

How long is US 20 over C and NW Railroad?

The structure is 270 ft (82.3 m) long with a longest span of 104 ft (31.7 m) and a deck 87 ft wide.

Who owns US 20 over C and NW Railroad?

It is owned by the State Highway Agency.