US Bridges

West Portal Drive over North Inlet

Fair

Grand County, Colorado · Road to Adams Falls · Structure no. 560.01

Built
1950
75 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
99 ft
1 main span
Daily traffic
924
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

West Portal Drive over North Inlet is a steel stringer/multi-beam or girder carrying West Portal Drive over North Inlet in Grand County, Colorado. It was built in 1950, so it is 75 years old, older than the Colorado average of 42.2 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 924 vehicles a day, roughly 29% of them trucks, projected to reach 1,090 by 2042. The structure is 99 ft (30.3 m) long and 38 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesWest Portal Drive
CrossesNorth Inlet
LocationRoad to Adams Falls
RouteCity Street 0
CountyGrand County
StateColorado
Coordinates40.25296, -105.81477
Functional classRural Minor Collector

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating40 US tons
Inventory rating34.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length99 ft (30.3 m)
Longest span93 ft (28.4 m)
Deck width38 ft (11.7 m)
Roadway width31 ft (9.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic924 (2023)
Projected traffic1,090 by 2042
Trucks29%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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 West Portal Drive over North Inlet built?

It was built in 1950, making it 75 years old in 2025.

What condition is West Portal Drive over North Inlet 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 September 2023.

How much traffic does West Portal Drive over North Inlet carry?

About 924 vehicles per day (2023 count), of which roughly 29% are trucks.

How long is West Portal Drive over North Inlet?

The structure is 99 ft (30.3 m) long with a longest span of 93 ft (28.4 m) and a deck 38 ft wide.

Who owns West Portal Drive over North Inlet?

It is owned by the City or Municipal Highway Agency.