Bridges in New Hampshire

2,549Total Bridges

1,303Good

1,054Fair

192Poor

Bridge Conditions in New Hampshire

New Hampshire has 2,549 bridges tracked in the National Bridge Inventory. Of these, 192 (7%) are rated as poor condition — meaning at least one major component has significant deterioration. The average bridge in New Hampshire is 57 years old.

New Hampshire Bridge Facts

Total Bridges	2,549
Good Condition	1,303
Fair Condition	1,054
Poor Condition	192
Average Bridge Age	57 years
Longest Bridge	2784.1 ft

Longest Bridges in New Hampshire

US 1 Bypass over Piscataqua River Rr2784.1 ftGood Nh119 over Connecticut River Necrr1905.5 ftGood I-95 over Preble Way Csx1810.0 ftFair US 4 Nh 16 Tpk SB over Little Bay RD1648.6 ftGood US 4 Nh 16 Tpk NB over Little Bay RD1598.1 ftGood

Counties in New Hampshire

Belknap112 bridges5 poor Carroll193 bridges10 poor Cheshire194 bridges22 poor Coos189 bridges10 poor Grafton547 bridges43 poor Hillsborough385 bridges31 poor Merrimack326 bridges27 poor Rockingham309 bridges22 poor Strafford136 bridges13 poor Sullivan158 bridges9 poor

Poor Condition Bridges in New Hampshire

Bridge	County	Length	Traffic	Year
I-89 over South Street	Merrimack	55.1 ft	46,612	1959
I-293 Fee Tpk over Stark Way	Hillsborough	29.9 ft	46,106	1956
Us202 over Nhrr Constitution Av.	Merrimack	155.8 ft	45,555	1958
Fee Tpk SB over Pennichuck Brook	Hillsborough	89.9 ft	44,365	1954
I-393 US 4 Us202 over Fort Eddy RD	Merrimack	69.9 ft	40,527	1980
I-293 Nh 3a Tpk N over Black Brook	Hillsborough	74.1 ft	24,101	1956
Nh 9(loudon Road) over Merrimack River	Merrimack	524.9 ft	23,721	1966
Nh 16 Sp Tpk SB over Cocheco River	Strafford	267.1 ft	23,607	1957
Nh 16 Sp Tpk NB over Cocheco River	Strafford	267.1 ft	22,560	1957
I-393 US 4 Us202 over I-93	Merrimack	167.0 ft	22,391	1958
I-89 NB over Connecticut River Necrr	Grafton	847.1 ft	22,288	1966
Nh 16 Sp Tpk NB over Nh108 Csx(abd)	Strafford	206.0 ft	22,163	1957
I-293 Nh 3a Tpk S over Black Brook	Hillsborough	74.1 ft	22,005	1956
Nh 16 Sp Tpk SB over Nh108 Csx(abd)	Strafford	299.9 ft	21,323	1957
I-89 SB over Connecticut River Necrr	Grafton	846.1 ft	21,268	1966
I-89 SB over Turkey Pond	Merrimack	240.2 ft	20,703	1959
I-89 NB over Turkey Pond	Merrimack	240.2 ft	20,387	1959
Nh 33 over Winnicut River	Rockingham	65.0 ft	17,736	1959
US 1 over Csx	Rockingham	42.0 ft	15,436	1935
Nh125 over Isinglass River	Strafford	119.1 ft	14,407	1951
US 1 over Csx(abd)	Rockingham	120.1 ft	14,314	1936
US 4 over Nh155a	Strafford	83.0 ft	13,387	1968
Salmon Street EB over Merrimack R Csx RD Ramp	Hillsborough	1023.0 ft	13,150	1970
US 3 over Baboosic Brook	Hillsborough	29.9 ft	13,024	1933
US 4 Mechanic ST over Mascoma River	Grafton	88.9 ft	12,803	1977
Nh 13 over Souhegan River	Hillsborough	111.9 ft	12,799	1931
Nh101 over Otter Brook	Cheshire	82.0 ft	11,538	1933
Nh 11 over Merrymeeting River	Belknap	35.1 ft	10,346	1934
Nh 1a over Hampton River	Rockingham	1199.1 ft	9,402	1949
Nh 12a over Nhrr	Grafton	145.0 ft	9,117	1949
Nh 12 over S Branch Ashuelot River	Cheshire	36.1 ft	8,976	1941
Oak Street over Csx	Strafford	65.0 ft	8,749	1890
Nh119 over Connecticut River	Cheshire	338.9 ft	8,535	1920
Nh119 over Connecticut River	Cheshire	296.9 ft	8,535	1920
Nh 12 over Nhrr(abd)	Cheshire	70.9 ft	8,066	1957
Nh 12 over Mill Brook	Cheshire	21.3 ft	6,478	1941
Baboosic Lake Road over Fee Tpk	Hillsborough	167.0 ft	6,359	1954
Nh112 Kancamagus over Pemigewasset River	Grafton	87.9 ft	6,210	1933
Gulf Road over Salmon Falls River	Strafford	488.8 ft	6,132	1950
Main Street over Beaver Brook	Hillsborough	45.9 ft	6,111	1900
Maplewood Avenue over North Mill Pond	Rockingham	24.9 ft	5,829	1940
Us202 Nh123 over Contoocook River	Hillsborough	175.9 ft	5,773	1942
Nh 3a over Newfound River	Grafton	60.0 ft	5,690	1924
Nh120 Park Lot Ped over Nhrr(abd)	Grafton	27.9 ft	5,317	1969
Nh 11 over Poor Farm Brook	Belknap	29.9 ft	5,227	1966
Bridge Street over Spicket River	Rockingham	28.9 ft	4,883	1900
US 2 over Pea Brook	Coos	27.9 ft	4,334	1932
Nh152 over North River	Rockingham	23.0 ft	3,719	1925
Maple AVE over Black Brook	Cheshire	23.0 ft	3,502	1961
Nh 31 over Stony Brook	Hillsborough	23.0 ft	3,496	1929
Nh 1b over Little Harbor	Rockingham	253.6 ft	3,359	1942
Nh111a over Exeter River	Rockingham	79.1 ft	3,259	1978
Nh 32 over Martin Brook	Cheshire	26.9 ft	2,956	1929
Nh104 over Smith River	Merrimack	106.0 ft	2,913	1940
Nh 3a over Newfound River	Grafton	71.9 ft	2,878	1949
Nh 49 over Mad River	Grafton	540.0 ft	2,828	1979
US 3 over Lost River	Grafton	68.9 ft	2,784	1931
Cornish Toll Br RD over Connecticut River	Sullivan	449.1 ft	2,722	1866
Nh 11b over Gunstock River	Belknap	24.9 ft	2,690	1941
Nh 11 over Nhrr(abd)	Merrimack	179.1 ft	2,674	1929
Nh 11 over Sucker Brook	Merrimack	27.9 ft	2,674	1929
Nh 11 over Sucker Brook	Merrimack	27.9 ft	2,674	1929
US 4 over Blackwater River	Merrimack	75.1 ft	2,652	1933
Us202 Nh 9 over Ash Brook	Merrimack	29.9 ft	2,610	1970
Antrim Road over Monadnock Mill Canal	Hillsborough	27.9 ft	2,233	1922
Christian Hill RD over Nhrr(abd)	Cheshire	74.1 ft	2,191	1930
East Thetford Road over Connecticut River	Grafton	471.1 ft	2,160	1937
US 4 over Smith River	Merrimack	69.9 ft	2,087	1929
School Street over Ammonoosuc River	Grafton	222.1 ft	2,087	1960
Hall Road over Little Cohas Brook	Rockingham	24.0 ft	1,964	1974
Nh 49 over Pemigewasset River	Grafton	216.9 ft	1,917	1928
Wilton Road over Souhegan River	Hillsborough	172.9 ft	1,866	1938
River Road over Piscataquog River	Hillsborough	117.1 ft	1,866	1940
Hanson Road over Exeter River	Rockingham	30.8 ft	1,854	1932
Cocheco Road over Cocheco River	Strafford	64.0 ft	1,773	1953
Nh127 over Warner River	Merrimack	123.0 ft	1,581	1937
Nh 18 over Connecticut River	Grafton	533.1 ft	1,508	1934
Nh127 over Blackwater River	Merrimack	166.0 ft	1,472	1941
Nh118 over Indian River	Grafton	35.1 ft	1,436	1948
Tirrell Hill Road over Black Brook	Hillsborough	42.0 ft	1,387	1994
Plains Road over Sugar River	Sullivan	193.9 ft	1,376	1974
Nh103 over I-89 SB Warner River	Merrimack	245.1 ft	1,372	1966
US 3 over Bog Brook	Grafton	40.0 ft	1,193	1929
Chesham Road over Minnewawa Brook	Cheshire	89.9 ft	1,191	1939
Nh142 over Ammonoosuc River	Grafton	124.0 ft	1,167	1927
River Road South over Partridge Brook	Cheshire	147.3 ft	1,167	1937
Temple Road over Blood Brook	Hillsborough	48.9 ft	1,167	1901
Dorchester Road over Grant Brook	Grafton	41.0 ft	1,132	1952
Cate Street over Hodgson Brook	Rockingham	37.1 ft	1,096	1940
Trues Brook Road over Bloods Brook	Grafton	65.0 ft	1,089	1952
Nh 16a over E Br Saco River	Carroll	80.1 ft	1,078	1928
Nh 25 over Oliverian Brook	Grafton	54.1 ft	1,072	1960
Nh 12a over Sugar River	Sullivan	280.8 ft	1,067	1967
Whitcomb Mills RD over White Brook	Cheshire	23.0 ft	826	1940
Nh 25a over Brackett Brook	Grafton	40.0 ft	826	1929
Nh 25a over Baker Pond Brook	Grafton	24.0 ft	826	1929
Spring Street over Cocheco River	Strafford	39.0 ft	770	1926
Contoocook Falls R over Contoocook River	Hillsborough	224.1 ft	712	1933
Nh175 over Pemigewasset River	Grafton	183.1 ft	674	1939
Potato Road over Indian River	Grafton	54.1 ft	655	1930