US Bridges

Coastal HGWY/SR1 over Mispillion River

Fair

Sussex County, Delaware · Milford · Structure no. 3003S007

Built
1971
54 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
313 ft
3 main spans
Daily traffic
14,302
2023 count
Owner
State
State Highway Agency

About this bridge

Coastal HGWY/SR1 over Mispillion River is a steel continuous stringer/multi-beam or girder carrying Coastal HGWY/SR1 over Mispillion River in Sussex County, Delaware. It was built in 1971, so it is 54 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 5 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 14,302 vehicles a day, roughly 5% of them trucks, projected to reach 13,096 by 2042. The structure is 313 ft (95.3 m) long and 47 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesCoastal HGWY/SR1
CrossesMispillion River
LocationMilford
RouteState Highway 1
CountySussex County
StateDelaware
Coordinates38.91734, -75.40268
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating37.1 US tons
Inventory rating28.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length313 ft (95.3 m)
Longest span127 ft (38.7 m)
Deck width47 ft (14.2 m)
Roadway width43 ft (13.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic14,302 (2023)
Projected traffic13,096 by 2042
Trucks5%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Coastal HGWY/SR1 over Mispillion River built?

It was built in 1971, making it 54 years old in 2025.

What condition is Coastal HGWY/SR1 over Mispillion River 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 July 2023.

How much traffic does Coastal HGWY/SR1 over Mispillion River carry?

About 14,302 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is Coastal HGWY/SR1 over Mispillion River?

The structure is 313 ft (95.3 m) long with a longest span of 127 ft (38.7 m) and a deck 47 ft wide.

Who owns Coastal HGWY/SR1 over Mispillion River?

It is owned by the State Highway Agency.