US Bridges

RM 1871 over Llano River

Good

Mason County, Texas · 9.10 MI SW of US 87 · Structure no. 141570175301005

Built
2021
4 years old
Condition
Good
inspected June 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
846 ft
9 main spans
Daily traffic
220
2021 count
Owner
State
State Highway Agency

About this bridge

RM 1871 over Llano River is a prestressed concrete stringer/multi-beam or girder carrying RM 1871 over Llano River in Mason County, Texas. It was built in 2021, so it is 4 years old, younger than the Texas average of 44.4 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 220 vehicles a day, roughly 24% of them trucks, projected to reach 1 by 1900. The structure is 846 ft (257.9 m) long and 32 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

CarriesRM 1871
CrossesLlano River
Location9.10 MI SW of US 87
RouteState Highway 1871
StateTexas
Coordinates30.65801, -99.32451
Functional classRural Major Collector

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.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation8: Equal to present desirable criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating60 US tons
Inventory rating36 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans9
Design loadHL 93
Structure length846 ft (257.9 m)
Longest span101 ft (30.8 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic220 (2021)
Projected traffic1 by 1900
Trucks24%
Lanes on structure2
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 RM 1871 over Llano River built?

It was built in 2021, making it 4 years old in 2025.

What condition is RM 1871 over Llano River 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 June 2023.

How much traffic does RM 1871 over Llano River carry?

About 220 vehicles per day (2021 count), of which roughly 24% are trucks.

How long is RM 1871 over Llano River?

The structure is 846 ft (257.9 m) long with a longest span of 101 ft (30.8 m) and a deck 32 ft wide.

Who owns RM 1871 over Llano River?

It is owned by the State Highway Agency.