US Bridges

FM 1660 over S Fk Mustang Ck

Fair

Williamson County, Texas · 2.40 MI N of US 79 · Structure no. 142460156601007

Built
1966
59 years old, rebuilt 1991
Condition
Fair
inspected March 2023
Type
Culvert
Concrete
Length
21 ft
3 main spans
Daily traffic
1,801
2021 count
Owner
State
State Highway Agency

About this bridge

FM 1660 over S Fk Mustang Ck is a concrete culvert carrying FM 1660 over S Fk Mustang Ck in Williamson County, Texas. It was built in 1966 and reconstructed in 1991, so it is 59 years old, older than the Texas average of 44.4 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 1,801 vehicles a day, roughly 17% of them trucks, projected to reach 2,521 by 2041. The structure is 21 ft (6.4 m) long and 52 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesFM 1660
CrossesS Fk Mustang Ck
Location2.40 MI N of US 79
RouteState Highway 1660
CountyWilliamson County
StateTexas
Coordinates30.57668, -97.54567
Functional classRural Major 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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44 US tons
Inventory rating26 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length21 ft (6.4 m)
Longest span6 ft (1.8 m)
Deck width52 ft (15.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,801 (2021)
Projected traffic2,521 by 2041
Trucks17%
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

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM 1660 over S Fk Mustang Ck built?

It was built in 1966, making it 59 years old in 2025. It was reconstructed in 1991.

What condition is FM 1660 over S Fk Mustang Ck 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 March 2023.

How much traffic does FM 1660 over S Fk Mustang Ck carry?

About 1,801 vehicles per day (2021 count), of which roughly 17% are trucks.

How long is FM 1660 over S Fk Mustang Ck?

The structure is 21 ft (6.4 m) long with a longest span of 6 ft (1.8 m) and a deck 52 ft wide.

Who owns FM 1660 over S Fk Mustang Ck?

It is owned by the State Highway Agency.