Grafton County Bridge Report Card

Grafton County scores 68 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

D68 / 100

Local infrastructure snapshot

Grafton County, New Hampshire

Grafton County has 547 bridges in the National Bridge Inventory, with 43 rated poor and 19 rated scour-critical. Its poor-condition share of 7.9% is above the 7.5% statewide average. Poor-condition bridges carry about 111,914 daily vehicle crossings.

547Total Bridges

43Poor (7.9%)

242Fair (44.2%)

19Scour-Critical

Quote-Ready Local Facts

7.9%of county bridges are in poor condition, compared with 7.5% statewide and 6.7% nationally.

111,914daily vehicle crossings are on poor-condition bridges in the county.

19bridges are rated scour-critical, or 3.5% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Grafton County a Bridge Condition Exposure Score of 68/100 (D). The county has 547 bridges in the National Bridge Inventory, including 43 in poor condition and 19 rated scour-critical. Poor-condition bridges carry about 111,914 daily vehicle crossings. Poor condition does not mean unsafe; bridges judged unsafe are closed or restricted by transportation agencies.

Download all county report-card scores as CSV.

How the Score Breaks Down

Factor	Weight	County Value	Penalty
Poor-condition bridge share	40	7.9%	15.7
Poor-condition traffic exposure	25	6.0% of measured traffic	4.5
Scour-critical bridge share	20	3.5%	6.9
Average age vs national baseline	10	59 years vs 48 nationally	4.6
Traffic-data completeness	5	1,850,486 measured daily crossings	0.0

Score = 100 minus weighted penalties. The score is a comparative research signal, not an official safety rating. Read the full methodology.

County Comparisons

County Poor-Condition Share	7.9%
State Poor-Condition Share	7.5%
National Poor-Condition Share	6.7%
County Scour-Critical Share	3.5%
Average Bridge Age	59 years
Poor-Condition Traffic Exposure	111,914 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeI-89 NB over Connecticut River Necrr — 22,288 vehicles/day Oldest Listed BridgeWest Bath Road over Ammonoosuc R Nhrr(abd) — built in 1832 All County BridgesBrowse every bridge record in Grafton County.

Top Bridges to Watch in Grafton County

Bridge	Reason	Condition	Daily Traffic	Year Built
I-89 NB over Connecticut River Necrr	Poor condition + traffic exposure	Poor	22,288	1966
I-89 SB over Connecticut River Necrr	Poor condition + traffic exposure	Poor	21,268	1966
Nh 49 over Mad River	Poor condition + traffic exposure	Poor	2,828	1979
Nh 49 over Pemigewasset River	Poor condition + traffic exposure	Poor	1,917	1928
Trues Brook Road over Bloods Brook	Poor condition + traffic exposure	Poor	1,089	1952
Nh 25a over Brackett Brook	Poor condition + traffic exposure	Poor	826	1929
Washburn Road over Patten Brook	Poor condition + traffic exposure	Poor	289	1950
US 4 Mechanic ST over Mascoma River	Poor condition + traffic exposure	Poor	12,803	1977
Nh 12a over Nhrr	Poor condition + traffic exposure	Poor	9,117	1949
Nh112 Kancamagus over Pemigewasset River	Poor condition + traffic exposure	Poor	6,210	1933

Important safety note

Poor condition does not mean a bridge is unsafe. It means at least one major component has significant deterioration and the bridge is a priority for maintenance, repair, or replacement. Bridges judged unsafe are closed or restricted by transportation agencies.