US Bridges

RTE 1 over Mamaroneck River

Fair

Westchester County, New York · JCT US 1 & Mamaroneck Rvr · Structure no. 000000001000040

Built
1895
130 years old, rebuilt 2024
Condition
Fair
inspected October 2024
Type
Arch - Deck
Masonry
Length
70 ft
1 main span
Daily traffic
15,757
2019 count
Owner
State
State Highway Agency

About this bridge

RTE 1 over Mamaroneck River is a masonry arch - deck carrying RTE 1 over Mamaroneck River in Westchester County, New York. It was built in 1895 and reconstructed in 2024, so it is 130 years old, older than the New York average of 53 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 15,757 vehicles a day, roughly 1% of them trucks, projected to reach 15,831 by 2041. The structure is 70 ft (21.3 m) long and 72 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesRTE 1
CrossesMamaroneck River
LocationJCT US 1 & Mamaroneck Rvr
RouteU.S. Route 1
CountyWestchester County
StateNew York
Coordinates40.9489, -73.73262
Functional classUrban Other Principal Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionOctober 2024
Inspection intervalevery 24 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 alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating45.9 US tons
Inventory rating19.1 US tons

Structure

Structure typeArch - Deck
MaterialMasonry
DeckNot applicable
Main spans1
Design loadHL 93
Structure length70 ft (21.3 m)
Longest span50 ft (15.2 m)
Deck width72 ft (21.8 m)
Roadway width53 ft (16.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic15,757 (2019)
Projected traffic15,831 by 2041
Trucks1%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedWidening with deck rehabilitation or replacement
Estimated improvement cost$6.9 million (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was RTE 1 over Mamaroneck River built?

It was built in 1895, making it 130 years old in 2025. It was reconstructed in 2024.

What condition is RTE 1 over Mamaroneck 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 October 2024.

How much traffic does RTE 1 over Mamaroneck River carry?

About 15,757 vehicles per day (2019 count), of which roughly 1% are trucks.

How long is RTE 1 over Mamaroneck River?

The structure is 70 ft (21.3 m) long with a longest span of 50 ft (15.2 m) and a deck 72 ft wide.

Who owns RTE 1 over Mamaroneck River?

It is owned by the State Highway Agency.