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Bridge conditions in Mercer County, New Jersey

413 inventoried bridges · 36 rated poor · 2025 National Bridge Inventory

United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled August 20, 2026

36 of the 413 bridges the federal inventory lists in Mercer County are rated poor; the rest split 165 good and 212 fair.

36 of the 413 bridges in Mercer County, New Jersey, are rated in poor condition (8.7%) in the 2025 National Bridge Inventory, as of August 20, 2026.
165 bridges (40.0%) are rated good and 212 (51.3%) fair.
The median Mercer County bridge was built in 1981.
The busiest poor-rated bridge is US Route 1 over D&r Canal (built 1973), carrying about 43,117 vehicles a day.

Good 40.0% · Fair 51.3% · Poor 8.7% of 413 bridges

Bridges rated poor

Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.

Bridge	Built	Vehicles/day	Condition
US Route 1 over D&r Canal	1973	43,117	Poor
Quaker Bridge Road over Amtrak	1966	33,105	Poor
US 130 over Millstone River	1936	32,880	Poor
South Olden Avenue over Amtrak NE Corridor	1923	22,960	Poor
U.S. 1B over Five Mile Run	1928	22,136	Poor
Qukrbrdg Rd CR533 over Miry Run	1936	20,985	Poor
Clarksville Road over Amtrak NE Corridor	1900	15,867	Poor
N Olden Ave CR 622 over Pcrr Sidetrack (aban)	1930	15,362	Poor
Prospect Street over Shabakunk Creek	1930	14,195	Poor
Nj 64 over Amtrak	1939	13,685	Poor
Whitehd Rd(co 616) over Delaware & Raritan Canal	1954	13,610	Poor
Washington Rd over Carnegie Lake	1905	13,599	Poor
Nj 29 over Nj 175& D&r Canal Feeder	1960	13,593	Poor
Princeton Pike over I-295 Ramps B and D	1973	13,255	Poor
Yrdvlle-allntwn Rd over US 130	1951	12,471	Poor
East State Street over Amtrak NE Corridor	1911	9,247	Poor
Millstone Road over Millstone River	1967	8,435	Poor
South Clinton Ave over Amtrak NE Corridor	1890	7,956	Poor
Wash Crsg Rd CR546 over Trenton Line (csxt)	1930	7,472	Poor
So Broad ST(US206) over Assunpink Creek	1843	7,285	Poor
West Hanover St. over Del. & Rar. Canal Feeder	1916	7,233	Poor
Penn-ctrville Rd over Stony Brook	1987	7,072	Poor
Prospect Street over Del-Raritan St Prk Trail	1913	6,876	Poor
County Route 569 over Bedens Brook	1973	6,245	Poor
Lincoln AVE(CR626) over Amtrak & Assunpink Crk	1931	5,815	Poor
US 206 (N. Broad) over D&r Feeder Canal	1917	5,391	Poor
Iron Bridge Road over Crosswicks Creek	1868	3,122	Poor
Center Street over Amtrak NE Corridor	1930	2,642	Poor
Carnegie Road over Delaware & Raritan Canal	1951	2,506	Poor
Monmouth Street over Amtrak NE Corridor	1911	2,114	Poor
Grant Street over D&r Canal Feeder	1950	1,140	Poor
Chestnut Avenue over Amtrak	1930	1,122	Poor
Yard Road over Baldwins Creek	1969	478	Poor
Montgomery St over Assunpink Creek	1873	135	Poor
River Drive over D&r Feeder Canal	1953	60	Poor
Old Nj 27 over Millstone River	1798	24	Poor

Busiest bridges in the county

Bridge	Built	Vehicles/day	Condition
Route 29 Rampb over Assunpink Creek	1969	163,000	Fair
Nj Tpk(i-95) over Cedar Swamp Brook	1950	128,068	Fair
US 1 over Duck Pond Run	1928	120,147	Fair
I-295 Southbound over Franklin Corner Road	1973	100,463	Fair
Nj Tpk (I-95) over Nj 33	1950	99,482	Fair
Nsi & Sni Roadways over Monmouth Street	1950	99,482	Fair
Nsi & Sni Roadways over Millstone River	1950	99,482	Fair
Nj Tpk(i-95) over Assunpink Creek	1950	97,420	Fair
Sni & Nsi Roadways over Rocky Brook	1950	97,420	Fair
US 1 over Millstone River	2010	93,321	Good

Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.

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Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.