Suffolk County Bridge Report Card

Suffolk County scores 69 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

D69 / 100

Local infrastructure snapshot

Suffolk County, Massachusetts

Suffolk County has 490 bridges in the National Bridge Inventory, with 49 rated poor and 2 rated scour-critical. Its poor-condition share of 10.0% is above the 9.4% statewide average. Poor-condition bridges carry about 1,314,400 daily vehicle crossings.

490Total Bridges

49Poor (10.0%)

331Fair (67.6%)

2Scour-Critical

Quote-Ready Local Facts

10.0%of county bridges are in poor condition, compared with 9.4% statewide and 6.7% nationally.

1,314,400daily vehicle crossings are on poor-condition bridges in the county.

2bridges are rated scour-critical, or 0.4% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Suffolk County a Bridge Condition Exposure Score of 69/100 (D). The county has 490 bridges in the National Bridge Inventory, including 49 in poor condition and 2 rated scour-critical. Poor-condition bridges carry about 1,314,400 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	10.0%	20.0
Poor-condition traffic exposure	25	7.9% of measured traffic	5.9
Scour-critical bridge share	20	0.4%	0.8
Average age vs national baseline	10	59 years vs 48 nationally	4.3
Traffic-data completeness	5	16,637,807 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	10.0%
State Poor-Condition Share	9.4%
National Poor-Condition Share	6.7%
County Scour-Critical Share	0.4%
Average Bridge Age	59 years
Poor-Condition Traffic Exposure	1,314,400 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeHWY Morrssey Blv over Water Dorchester Bay — 78,900 vehicles/day Oldest Listed BridgeHWY Adams ST over Water Neponset River — built in 1765 All County BridgesBrowse every bridge record in Suffolk County.

Top Bridges to Watch in Suffolk County

Bridge	Reason	Condition	Daily Traffic	Year Built
HWY Morrssey Blv over Water Dorchester Bay	Poor condition + traffic exposure	Poor	78,900	1927
I 93 Bt Sb4-n Abt over HWY Connectors D & K	Poor condition + traffic exposure	Poor	77,596	1970
I 90 EB over Rr Mbta	Poor condition + traffic exposure	Poor	76,373	1965
I 90 WB over Rr Mbta	Poor condition + traffic exposure	Poor	74,344	1965
HWY Storrw DR WB over HWY Storrow DR EB	Poor condition + traffic exposure	Poor	57,770	1951
ST 1 A/lee Brbnk over St145 Revere Bch PKWY	Poor condition + traffic exposure	Poor	55,630	1934
HWY Bowker Int over Comb I 90 & Mbta	Poor condition + traffic exposure	Poor	55,075	1965
US 1 Nb/low Deck over HWY Chelsea Local Stre	Poor condition + traffic exposure	Poor	42,492	1950
US 1 Sb/uppr Deck over US 1 Nb/chel Lwr Deck	Poor condition + traffic exposure	Poor	41,655	1950
HWY Blue Hill Av over Rr Mbta	Poor condition + traffic exposure	Poor	41,250	1902

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.