US Bridges

Carter RD over Mill Creek

Fair

Kent County, Delaware · South of Smyrna · Structure no. 2137B137

Built
1970
55 years old
Condition
Fair
inspected August 2021
Type
Culvert
Concrete
Length
31 ft
2 main spans
Daily traffic
7,264
2020 count
Owner
State
State Highway Agency

About this bridge

Carter RD over Mill Creek is a concrete culvert carrying Carter RD over Mill Creek in Kent County, Delaware. It was built in 1970, so it is 55 years old, older than the Delaware average of 47.3 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 7,264 vehicles a day, roughly 7% of them trucks, projected to reach 9,028 by 2042. The structure is 31 ft (9.4 m) long and 40 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesCarter RD
CrossesMill Creek
LocationSouth of Smyrna
RouteCounty Highway 137
CountyKent County
StateDelaware
Coordinates39.28665, -75.61052
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 protection8 Very GoodNo problems noted.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2021
Inspection intervalevery 48 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 rating63.6 US tons
Inventory rating48.9 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length31 ft (9.4 m)
Longest span14 ft (4.3 m)
Deck width40 ft (12.2 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,264 (2020)
Projected traffic9,028 by 2042
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 Carter RD over Mill Creek built?

It was built in 1970, making it 55 years old in 2025.

What condition is Carter RD over Mill Creek 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 August 2021.

How much traffic does Carter RD over Mill Creek carry?

About 7,264 vehicles per day (2020 count), of which roughly 7% are trucks.

How long is Carter RD over Mill Creek?

The structure is 31 ft (9.4 m) long with a longest span of 14 ft (4.3 m) and a deck 40 ft wide.

Who owns Carter RD over Mill Creek?

It is owned by the State Highway Agency.