June 9, 2015 | Number of The Day
Number of functionally obsolete bridges in NJ

Out of New Jersey’s 6,554 bridges, 1,710 are functionally obsolete, according to NJ Transportation by the Numbers from the U.S. Department of Transportation.

A bridge is considered functionally obsolete if it can’t meet current design standards.

By that measure, 26.2 percent of New Jersey’s bridges are obsolete, compared with 13.9 percent of all bridges in the United States. The country has 83,391 obsolete bridges out of 605,471 bridges in total.

In addition, 624 (9.9 percent) of New Jersey’s bridges are structurally deficient (compared with 11 percent of all bridges — or 63,207 — nationally). This means that the bridge in question needs to be repaired or a specific component needs to be replaced. It does not imply that the bridge is in danger of collapse. The classification is assigned when one or more aspects of a bridge (superstructure, deck, or substructure, for example) are rated four or less on a nine-point scale.

It’s not just New Jersey’s bridges that have problems; anyone who’s spent a few hours on its highways and byways knows it can be a rough ride. The state has 39,272 miles of public road, with only 50.4 percent having acceptable ride quality, according to the Transportation Department. Overall, 81.3 percent of the country’s roads deliver an acceptable ride. Ride quality is calculated using the International Roughness Index, a measurement of how much a road deviates from a smooth surface in inches per mile. To be rated acceptable, a road must have an IRI value of less than or equal to 170 inches per mile.