US Bridges

Mason LN over Grand Glaize CR

PoorPosted for load

St. Louis County, Missouri · S 32 T 45 N R 5 E · Structure no. 15605

Built
1960
65 years old
Condition
Poor
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
48 ft
1 main span
Daily traffic
430
2024 count
Owner
County
County Highway Agency

About this bridge

Mason LN over Grand Glaize CR is a steel stringer/multi-beam or girder carrying Mason LN over Grand Glaize CR in St. Louis County, Missouri. It was built in 1960, so it is 65 years old, older than the Missouri average of 45.1 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 3 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. Its operating status is: posted for load restriction.

It carries about 430 vehicles a day, roughly 2% of them trucks, projected to reach 581 by 2044. The structure is 48 ft (14.6 m) long and 25 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesMason LN
CrossesGrand Glaize CR
LocationS 32 T 45 N R 5 E
RouteCounty Highway 0
CountySt. Louis County
StateMissouri
Coordinates38.59218, -90.47831
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.
Superstructure3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating37.7 US tons
Inventory rating22.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length48 ft (14.6 m)
Longest span38 ft (11.6 m)
Deck width25 ft (7.6 m)
Roadway width19 ft (5.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic430 (2024)
Projected traffic581 by 2044
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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$569,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Mason LN over Grand Glaize CR built?

It was built in 1960, making it 65 years old in 2025.

What condition is Mason LN over Grand Glaize CR 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 April 2024.

How much traffic does Mason LN over Grand Glaize CR carry?

About 430 vehicles per day (2024 count), of which roughly 2% are trucks.

How long is Mason LN over Grand Glaize CR?

The structure is 48 ft (14.6 m) long with a longest span of 38 ft (11.6 m) and a deck 25 ft wide.

Who owns Mason LN over Grand Glaize CR?

It is owned by the County Highway Agency.