US Bridges

Lower Ashby Road over Souhegan River

Good

Hillsborough County, New Hampshire · 0.2 MI FR Nh RTE 123A · Structure no. 018601370006200

Built
2006
19 years old
Condition
Good
inspected August 2024
Type
Frame
Concrete
Length
25 ft
1 main span
Daily traffic
1,167
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Lower Ashby Road over Souhegan River is a concrete frame carrying Lower Ashby Road over Souhegan River in Hillsborough County, New Hampshire. It was built in 2006, so it is 19 years old, younger than the New Hampshire average of 56.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 1,167 vehicles a day, roughly 4% of them trucks, projected to reach 1,727 by 2043. The structure is 25 ft (7.6 m) long and 27 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

CarriesLower Ashby Road
CrossesSouhegan River
Location0.2 MI FR Nh RTE 123A
Coordinates42.72743, -71.84807
Functional classRural Minor Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating87.1 US tons
Inventory rating51.8 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, precast panels
Main spans1
Design loadHS 25 or greater
Structure length25 ft (7.6 m)
Longest span24 ft (7.3 m)
Deck width27 ft (8.2 m)
Roadway width23 ft (7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,167 (2023)
Projected traffic1,727 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible 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 Lower Ashby Road over Souhegan River built?

It was built in 2006, making it 19 years old in 2025.

What condition is Lower Ashby Road over Souhegan River 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 August 2024.

How much traffic does Lower Ashby Road over Souhegan River carry?

About 1,167 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Lower Ashby Road over Souhegan River?

The structure is 25 ft (7.6 m) long with a longest span of 24 ft (7.3 m) and a deck 27 ft wide.

Who owns Lower Ashby Road over Souhegan River?

It is owned by the City or Municipal Highway Agency.