It was 1792. George Washington was the president; the 13 stars on the US flag were arranged in a circle; and the U.S. Post Office Department and Mint were established. And in New Jersey, builders completed an 82-foot long bridge over Stony Brook in Princeton.
One of 6,566 Jersey bridges listed in the 2013 National Bridge Inventory, Bridge #1129155 is the oldest such structure still in use in the state. According to the NBI, there are exactly 100 spans built prior to 1900 that continue to carry traffic. The very oldest of these are clustered in three Central Jersey counties not far from Trenton, the state capital.
The operant word here is “oldest.” Of the 10 bridges listed, only two are structurally deficient and in need of repair. Four are functionally obsolete; they are inadequate for modern traffic but not in need of repair. And four are not at all deficient.
1. At 222 years old, the Stony Brook Bridge in Princeton in Mercer County is showing its age. It is rated structurally deficient, with a sufficiency rating of only 38.5 (out of 100). A National Historic Landmark, the bridge is located within the Princeton Battlefield-Stony Brook Settlement Historic District, which was settled between 1686 and 1777. On busy Route 206, located near Quaker Road, the two-lane arch masonry bridge carries an estimated 13,200 vehicles a day. It was reconstructed almost a century ago. The total repair cost for the bridge and its approaches was estimated at about $4.2 million in 2007, the most expensive to fix of the 10 oldest bridges.
2. Also in Princeton, Bridge #1105151 is the only other still functioning 18th century bridge in the inventory. Built in 1798, the bridge carries Old Route 27 over the Millstone River. Because Route 27 bypasses it, average daily traffic count is estimated at only 7 vehicles. It is eligible for the national register, but not listed. The 110-foot masonry arch bridge is two lanes wide. Its 33.8 rating merited it a rank of functionally obsolete, meaning its design is inadequate for modern traffic.
3. In Montgomery, in Somerset County, is another functionally obsolete bridge. Built in 1822, the one-lane span carries an estimated 1,720 vehicles a day along Opossum Road over Bedens Brook. The concrete arch bridge about 48-feet long is eligible for historic status. Three years ago, officials estimated it would cost about $1.2 million to bring the bridge up to modern standards.
4. Montgomery is home to another 192-year old bridge, on Dead Tree Run Road over Pike Run, near Mill Pond Road in Belle Mead. The 57-foot long one-lane bridge carries an estimated 890 vehicles a day. Also eligible to be a National Historic Landmark, the cost to repair this functionally obsolete bridge was estimated at $900,000 in 2014.
5. A third bridge in Montgomery made the list, built in 1825. Bridge #18B0301 carries Zion-Wertsville Road over Rock Brook, near Dutchtown Zion Road in Skillman. The 41-foot long one-lane bridge carries an estimated 530 vehicles a day. Rebuilt in 1891, this is the only other of the 10 oldest spans deemed structurally deficient. It had the lowest sufficiency rating — 17.9 out of 100. The cost to repair it was $931,000 in 2011.
6. The Route 29 bridge over Jacobs Creek in Ewing in Mercer County is the busiest span on the list, carrying an estimated 13,500 vehicles a day. The southernmost bridge on the list, Bridge #1110152 is located less than 1.5 miles north of the junction with I-95. At just 25-feet long, the masonry structure is also the shortest bridge on the list. Built in 1832 and rebuilt in 1941, its rating of 69.5 makes it the first of the oldest spans not considered to be deficient.
7. In East Amwell, in Hunterdon County, the Wertsville Road bridge over a tributary of Back Brook near Rocktown Road dates back to 1834. The two-lane span carried 2,271 vehicles a day in 2011. The steel truss bridge measuring about 44 feet was reconstructed in 2002 but still rates as functionally obsolete and has a sufficiency rating of 62.2.
8. Bridge #18G0403 in Franklin Township, Somerset County, had the highest sufficiency rating of the oldest bridges, an 86 out of 100. Located on Canal Road, crossing Six Mile Run, the bridge is just south of the Blackwells Mills Canal House. Also built in 1834, it’s the only other of the oldest bridges on the National Register of Historic Places. The northernmost bridge on the list, it carries about 3,300 cars a day over its 42 feet.
9. The 45-foot County Route 579 bridge over the Third Neshanic River tributary In Delaware Township, Hunterdon County, near Dunkard Church Road dates back to 1837 but is ineligible for national historic status. The masonry arch span carries 2,435 vehicles a day in 2011. Rebuilt in 2008, Bridge #1000022 has a sufficiency rating of 77.3.
10. The third bridge in Hunterdon is Bridge #100WE74 in West Amwell, on Woodsville Road, just off Route 31, crossing Peters Brook. The two-lane bridge built in 1840 carries 1,122 vehicles a day. The 40-foot long masonry arch span was rebuilt in 1920. While only rated 45.7 out of 100, it is not considered deficient.