US Bridges

Knapp RD over Flat Branch

Poor

Marion County, Indiana · 00.10 N of Maze RD · Structure no. 4900448

Built
1929
96 years old
Condition
Poor
inspected July 2024
Type
Slab
Concrete
Length
23 ft
1 main span
Daily traffic
233
2019 count
Owner
City
City or Municipal Highway Agency

About this bridge

Knapp RD over Flat Branch is a concrete slab carrying Knapp RD over Flat Branch in Marion County, Indiana. It was built in 1929, so it is 96 years old, older than the Indiana average of 46.6 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 233 vehicles a day, roughly 5% of them trucks, projected to reach 350 by 2039. The structure is 23 ft (7 m) long and 18 ft wide. If it were closed, the detour would be 2.5 mi (4 km).

Location

Open in Google Maps
CarriesKnapp RD
CrossesFlat Branch
Location00.10 N of Maze RD
RouteCity Street 125
CountyMarion County
StateIndiana
Coordinates39.64648, -86.00907
Functional classUrban Local

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.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJuly 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 rating35.9 US tons
Inventory rating35.9 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length23 ft (7 m)
Longest span20 ft (6 m)
Deck width18 ft (5.6 m)
Roadway width16 ft (4.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic233 (2019)
Projected traffic350 by 2039
Trucks5%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed2.5 mi (4 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$726,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Knapp RD over Flat Branch built?

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

What condition is Knapp RD over Flat Branch 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 July 2024.

How much traffic does Knapp RD over Flat Branch carry?

About 233 vehicles per day (2019 count), of which roughly 5% are trucks.

How long is Knapp RD over Flat Branch?

The structure is 23 ft (7 m) long with a longest span of 20 ft (6 m) and a deck 18 ft wide.

Who owns Knapp RD over Flat Branch?

It is owned by the City or Municipal Highway Agency.