US Bridges

Bridge Road over Blackwater River

Poor

Merrimack County, New Hampshire · 0.1 MI S Nh 11 · Structure no. 000800830009800

Built
1882
143 years old
Condition
Poor
inspected October 2024
Type
Truss - Thru
Wood or Timber
Length
65 ft
1 main span
Daily traffic
96
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Bridge Road over Blackwater River is a wood or timber truss - thru carrying Bridge Road over Blackwater River in Merrimack County, New Hampshire. It was built in 1882, so it is 143 years old, older than the New Hampshire average of 56.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 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.

It carries about 96 vehicles a day, roughly 4% of them trucks, projected to reach 142 by 2043. The structure is 65 ft (19.8 m) long and 19 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesBridge Road
CrossesBlackwater River
Location0.1 MI S Nh 11
CountyMerrimack County
StateNew Hampshire
Coordinates43.43498, -71.83616
Functional classRural 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2024
Inspection intervalevery 16 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating30.6 US tons
Inventory rating23 US tons

Structure

Structure typeTruss - Thru
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadUnknown
Structure length65 ft (19.8 m)
Longest span52 ft (15.8 m)
Deck width19 ft (5.8 m)
Roadway width9 ft (2.7 m)
Vertical clearance over deck12 ft (3.6 m)

Traffic and service

Average daily traffic96 (2023)
Projected traffic142 by 2043
Trucks4%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$314,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Bridge Road over Blackwater River built?

It was built in 1882, making it 143 years old in 2025.

What condition is Bridge Road over Blackwater River 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 October 2024.

How much traffic does Bridge Road over Blackwater River carry?

About 96 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Bridge Road over Blackwater River?

The structure is 65 ft (19.8 m) long with a longest span of 52 ft (15.8 m) and a deck 19 ft wide.

Who owns Bridge Road over Blackwater River?

It is owned by the City or Municipal Highway Agency.