State profile · Near national median SD

New Hampshire bridge safety

Condition ratings, load ratings, and structural-deficiency data for every public highway bridge in New Hampshire — drawn straight from the FHWA National Bridge Inventory.

2,542
Public bridges
43.0%
Good condition
7.1%
Poor condition
7.1%
Structurally deficient

Total Bridges

2,542

Public highway bridges in New Hampshire

Good Condition

43.0%

1,092 bridges rated 7-9

-7.0pp vs 50% benchmark

Poor Condition

7.1%

180 bridges rated 0-4

Structurally Deficient

7.1%

180 bridges flagged for repair priority

0.1pp vs national avg 7.0%

New Hampshire vs national bridge condition

New Hampshire — Good condition share 43.0%
National avg

Share of bridges rated 7-9 on the FHWA 0-9 scale (deck, superstructure, substructure all good).

New Hampshire — Structurally deficient share 23.6%
National avg

Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.0%.

Condition Distribution

Bridge inventory deck-condition mix — New Hampshire (FHWA NBI)

New Hampshire42.95830055074744%35.641227380015735%GoodFairPoorStructurally Deficient
Bridge inventory deck-condition mix — New Hampshire (FHWA NBI)

Counties (10)

Belknap 112 Carroll 193 Cheshire 192 Coos 188 Grafton 544 Hillsborough 385 Merrimack 326 Rockingham 308 Strafford 136 Sullivan 158

New Hampshire vs nearby ranks

Adjacent states on the structurally deficient leaderboard (lower share = better)

States are ranked by share of bridges flagged structurally deficient — the FHWA classification for any span where deck, superstructure, or substructure carries a condition rating of 4 or below. Lower percentages indicate stronger maintenance funding and inspection follow-through. States here sit immediately above and below New Hampshire on the same metric.

36

New York

6.90% top marginal rate
Structure
Progressive
Burden @ $100K
$19,132

21

Kentucky

7.06% top marginal rate
Structure
Progressive
Burden @ $100K
$14,554
Selected

33

New Hampshire

7.08% top marginal rate
Structure
Progressive
Burden @ $100K
$2,542

40

Oklahoma

7.50% top marginal rate
Structure
Progressive
Burden @ $100K
$22,733

35

New Mexico

7.61% top marginal rate
Structure
Progressive
Burden @ $100K
$368

Bridges Needing Most Attention in New Hampshire

Six lowest-condition bridges in New Hampshire, ranked by composite NBI rating. Each is inspected at least every 24 months.

OLD DEERFIELD ROAD

Poor

Over: BROOK

185 FT FROM NH RTE 43, Rockingham, NH

Built 1920 Load: 1.8 t ADT: 190

TEMPLETON TURNPIKE

Structurally Deficient

Over: PRIEST BROOK

1.9MI. RTE 119, Cheshire, NH

Built 1984 Load: 2.7 t ADT: 86

DUDLEY ROAD

Structurally Deficient

Over: LAMPREY RIVER

.23 MI JCT 101, Rockingham, NH

Built 1914 Load: 2.9 t ADT: 535

SHOP ROAD

Structurally Deficient

Over: NEEDLE SHOP BROOK

0.8 MI N NEW CHESTER RD, Merrimack, NH

Built 1930 Load: 3.3 t ADT: 63

WHITCOMB MILLS RD

Poor

Over: WHITE BROOK

0.06 MI FR ARCH ST, Cheshire, NH

Built 1940 Load: 3.6 t ADT: 814

LEIGHTON MEADOW RD

Structurally Deficient

Over: PHILLIPS BROOK

100 FT FR SULLIVAN RD 61, Coos, NH

Built 1940 Load: 3.6 t ADT: 90

All Bridges in New Hampshire

US 3,FEE TPK NB

Unknown

Over: SPIT BROOK ROAD

0.5 MI FROM MASS SL., Hillsborough, NH

Built 1993 ADT: 24,000

C-D ROAD

Unknown

Over: RAMP D,TOLL ACCESS DR

1.1 MI N MASS SL, Hillsborough, NH

Built 1996 ADT: 4,000

US 3,CD ROAD

Unknown

Over: SPIT BROOK ROAD

0.5 MI NORTH MASS SL, Hillsborough, NH

Built 1993 ADT: 24,000

FEE TPK NB OFFRAMP

Unknown

Over: FEE TPK SB OFF RAMP

1/8 MI WEST OF D W HYW., Hillsborough, NH

Built 2000 ADT: 10,000

CIRC HWY EB

Unknown

Over: DANIEL WEBSTER HWY

.3 MI EAST FEE TPK, Hillsborough, NH

Built 1993 ADT: 11,000

CIRC HWY WB

Unknown

Over: DANIEL WEBSTER HWY

.3 MI EAST FEE TPK, Hillsborough, NH

Built 1993 ADT: 11,000

US 4

Unknown

Over: RIVER ROAD,BMRR(ABD)

0.4MI FROM CONCORD TL, Merrimack, NH

Built 1958 ADT: 150

I-89

Unknown

Over: SOUTH STREET

BOW INTERCHANGE, Merrimack, NH

Built 1959 ADT: 7,000

I-93,FEE TPK SB

Unknown

Over: I-89,TURKEY RIVER, PED

BOW INTERCHANGE, Merrimack, NH

Built 2014 ADT: 21,300

GRANDVIEW ROAD

Unknown

Over: I-93,FEE TPK

0.4 MI JCT I-89, Merrimack, NH

Built 1978 ADT: 69,000

I-93,FEE TPK NB

Unknown

Over: I-89,TURKEY RIVER

BOW INTERCHANGE., Merrimack, NH

Built 2014 ADT: 21,300

I-93 NB C-D ROAD

Unknown

Over: I-89,TURKEY RIVER, PED

AT BOW INTERCHANGE, Merrimack, NH

Built 1978 ADT: 21,300

I-93,FEE TPK

Unknown

Over: DOW ROAD

1.7 MI JCT I-89, Merrimack, NH

Built 1957 ADT: 200

I-93,FEE TPK

Unknown

Over: ROBINSON ROAD

2.6 MI JCT RT 89, Merrimack, NH

Built 1957 ADT: 200

US 4 WB(HOIT RD)

Unknown

Over: I-93,US 4 WB

.6 MI EAST CANTERBURY TL, Merrimack, NH

Built 1958 ADT: 33,000

I-93,US 4 SB

Unknown

Over: SEWALLS FALLS ROAD

1.4MI SO OF JCT RT 3 BYP., Merrimack, NH

Built 1959 ADT: 3,900

I-93,US 4 NB

Unknown

Over: SEWALLS FALLS ROAD

1.4 MI. S. JCT. RT 3 BYP., Merrimack, NH

Built 1959 ADT: 3,900

WEST PORTSMOUTH ST

Unknown

Over: I-93,US 4

1.4 MI N. JCT 132, Merrimack, NH

Built 2000 ADT: 43,400

DELTA DRIVE

Unknown

Over: I-93,US 4

.6 MI NORTH OF JCT. US 4, Merrimack, NH

Built 1958 ADT: 48,000

US202

Unknown

Over: NHRR,CONSTITUTION AV.

.1 MI WEST JCT I-93, Merrimack, NH

Built 1958 ADT: 2,100

I-93 SB ON RAMP

Unknown

Over: NHRR,CONSTITUTION AV.

0.1 MI WEST OF JCT I-93, Merrimack, NH

Built 1949 ADT: 2,100

I-393,US 4,US202

Unknown

Over: I-93

0.4 MI. E. JCT US 3, Merrimack, NH

Built 1958 ADT: 62,000

I-393,US 4,US202W

Unknown

Over: PORTSMOUTH STREET

0.7 MI E EASTSIDE DRIVE, Merrimack, NH

Built 1978 ADT: 1,600

I-393,US 4,US202

Unknown

Over: FORT EDDY RD

0.2MI E JCT I-93, Merrimack, NH

Built 1980 ADT: 16,000

I-393,US 4,US202E

Unknown

Over: PORTSMOUTH STREET

0.7 MI E EASTSIDE DRIVE, Merrimack, NH

Built 1978 ADT: 1,600

NH132(EASTSIDE DR)

Unknown

Over: I-393,US 4,US202

1.4 MI EAST OF JCT I-93, Merrimack, NH

Built 1978 ADT: 39,351

NH 9(LOUDON RD)

Unknown

Over: STORRS STREET,CSX

.1 MI WEST OF JCT I-93, Merrimack, NH

Built 1970 ADT: 5,900

I-89 SB

Unknown

Over: STICKNEY HILL ROAD

1.7 MI NW JCT RT 13, Merrimack, NH

Built 1959 ADT: 1,400

I-93,FEE TPK

Unknown

Over: NH 9,LOUDON ROAD

1.6 MI N JCT RTE 3, Merrimack, NH

Built 1966 ADT: 26,000

I-89 NB

Unknown

Over: STICKNEY HILL ROAD

1.7 MI NW JCT RTE 13, Merrimack, NH

Built 1959 ADT: 1,400

NH106

Unknown

Over: I-393,US 4,US202

.4 MI W PEMBROOK TL, Merrimack, NH

Built 1988 ADT: 15,000

NH 9

Unknown

Over: I-393,US 4,US202

.2 MI W PEMBROOK TL, Merrimack, NH

Built 1988 ADT: 15,000

I-89 SB

Unknown

Over: SILK FARM ROAD

.5 MI N. OF JCT. RT. 13, Merrimack, NH

Built 1959 ADT: 100

I-89 NB

Unknown

Over: SILK FARM ROAD

.5 MI NW OF JCT RT 13, Merrimack, NH

Built 1959 ADT: 100

I-89 SB

Unknown

Over: NH 13

1.4 MI NW OF BOW TL, Merrimack, NH

Built 1959 ADT: 12,000

I-89 NB

Unknown

Over: NH 13

1.4 MI NW OF BOW T.L., Merrimack, NH

Built 1959 ADT: 12,000

I-93,FEE TPK

Unknown

Over: US 3,MANCHESTER STREET

1.2 MI NO OF JCT RT 3-A, Merrimack, NH

Built 2000 ADT: 11,000

I-93,FEE TPK SB

Unknown

Over: HALL STREET

.5 MI FROM JCT 3-A, Merrimack, NH

Built 1958 ADT: 8,200

I-93,FEE TPK NB

Unknown

Over: HALL STREET

.5 MI FROM JCT 3-A, Merrimack, NH

Built 1958 ADT: 8,200

NH 3A

Unknown

Over: I-93,FEE TPK

0.3 MI N OF BOW TL, Merrimack, NH

Built 2015 ADT: 69,000

OLD HILLSBORO ROAD

Unknown

Over: US202,NH 9

1.71 M. HILLSBORO TL, Merrimack, NH

Built 1974 ADT: 13,000

US202,NH 9

Unknown

Over: LIBERTY HILL ROAD

2.86 MI FROM HILLSBORO TL, Merrimack, NH

Built 1974 ADT: 250

NH114

Unknown

Over: US202,NH 9

3.05 MI FROM WARNER T.L., Merrimack, NH

Built 1974 ADT: 14,000

US202,NH 9

Unknown

Over: RUSH ROAD

.5 MI E. JCT. RT 114, Merrimack, NH

Built 1962 ADT: 250

I-93 SB

Unknown

Over: I-293,FEE TPK

AT JCT WITH FEET, Merrimack, NH

Built 1977 ADT: 39,000

I-93 RAMP

Unknown

Over: FEE TPK

AT JCT. WITH FEET., Merrimack, NH

Built 1976 ADT: 55,000

PINE STREET

Unknown

Over: I-93,FEE TPK

.5 MI SO. BOW TL, Merrimack, NH

Built 1978 ADT: 73,052

I-93,FEE TPK

Unknown

Over: CROSS ROAD

2.2 MI NO. MANCHESTER TL, Merrimack, NH

Built 1956 ADT: 1,300

I-93,FEE TPK RAMP

Unknown

Over: HACKETT HILL ROAD

2.5 MI N. MANCHESTER T.L, Merrimack, NH

Built 1978 ADT: 2,800

I-93,FEE TPK

Unknown

Over: RAMP A-B

2.7 MI NO MANCHESTER TL, Merrimack, NH

Built 1957 ADT: 4,800

Showing 151-200 of 2,542 bridges

Related

All states → | National rankings → | Understanding conditions → | SD bridges explained →
Data sourced from the FHWA National Bridge Inventory (NBI), latest released cycle. See our methodology for details. Retrieved and formatted by PlainBridges Editorial.

Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from the FHWA National Bridge Inventory (NBI). A "structurally deficient" rating is a repair-priority signal, not a closure or unsafe-to-cross designation. Consult a qualified civil engineer before making decisions based on this data.

Understanding Bridge Conditions

How FHWA rates bridge condition on a 0-9 scale.

Check Your Daily Bridges

How to look up bridge condition data for bridges on your route.

Read our methodology — how this data is sourced, computed, and verified.