US Bridges

FL-4184 over Animas River

Poor

San Juan County, New Mexico · 0.01 M E Aztec Blvd · Structure no. 000000000000119

Built
1929
96 years old
Condition
Poor
inspected February 2024
Type
Truss - Thru
Steel
Length
357 ft
3 main spans
Daily traffic
6,361
2023 count
Owner
State
State Highway Agency

About this bridge

FL-4184 over Animas River is a steel truss - thru carrying FL-4184 over Animas River in San Juan County, New Mexico. It was built in 1929, so it is 96 years old, older than the New Mexico average of 51.5 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 6,361 vehicles a day, roughly 5% of them trucks, projected to reach 8,650 by 2043. The structure is 357 ft (108.8 m) long and 21 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesFL-4184
CrossesAnimas River
Location0.01 M E Aztec Blvd
RouteCity Street 4184
CountySan Juan County
StateNew Mexico
Coordinates36.82565, -108.00315
Functional classUrban Minor Arterial

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
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
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 inspectionFebruary 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating59 US tons
Inventory rating26.8 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans3 (+2 approach)
Design loadH 15
Structure length357 ft (108.8 m)
Longest span200 ft (61 m)
Deck width21 ft (6.4 m)
Roadway width20 ft (6.2 m)
Vertical clearance over deck15 ft (4.5 m)

Traffic and service

Average daily traffic6,361 (2023)
Projected traffic8,650 by 2043
Trucks5%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$539,000 (2020 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was FL-4184 over Animas River built?

It was built in 1929, making it 96 years old in 2025.

What condition is FL-4184 over Animas River 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 February 2024.

How much traffic does FL-4184 over Animas River carry?

About 6,361 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is FL-4184 over Animas River?

The structure is 357 ft (108.8 m) long with a longest span of 200 ft (61 m) and a deck 21 ft wide.

Who owns FL-4184 over Animas River?

It is owned by the State Highway Agency.