US Bridges

SR 18 over I-75

Good

Monroe County, Georgia · 0.5 MI E of Forsyth · Structure no. 000000020700690

Built
1989
36 years old
Condition
Good
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
410 ft
4 main spans
Daily traffic
4,910
2024 count
Owner
State
State Highway Agency

About this bridge

SR 18 over I-75 is a steel stringer/multi-beam or girder carrying SR 18 over I-75 in Monroe County, Georgia. It was built in 1989, so it is 36 years old, younger than the Georgia average of 47.5 years.

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

It carries about 4,910 vehicles a day, roughly 1% of them trucks, projected to reach 6,210 by 2031. The structure is 410 ft (125 m) long and 60 ft wide.

CarriesSR 18
CrossesI-75
Location0.5 MI E of Forsyth
RouteState Highway 18
StateGeorgia
Coordinates33.02808, -83.90998
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating48.9 US tons
Inventory rating35.9 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length410 ft (125 m)
Longest span147 ft (44.8 m)
Deck width60 ft (18.2 m)
Roadway width56 ft (17.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,910 (2024)
Projected traffic6,210 by 2031
Trucks1%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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$3.1 million
NavigationNot applicable (no waterway)

Frequently asked questions

When was SR 18 over I-75 built?

It was built in 1989, making it 36 years old in 2025.

What condition is SR 18 over I-75 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 September 2024.

How much traffic does SR 18 over I-75 carry?

About 4,910 vehicles per day (2024 count), of which roughly 1% are trucks.

How long is SR 18 over I-75?

The structure is 410 ft (125 m) long with a longest span of 147 ft (44.8 m) and a deck 60 ft wide.

Who owns SR 18 over I-75?

It is owned by the State Highway Agency.