State website on bridge conditions is expanded

State website on bridge conditions is expanded

New York State Department of Transportation (NYSDOT) expanded the department's website detailing the condition of all the highway bridges in New York state. The site, www.nysdot.gov/bridgedata, includes the state condition rating for each bridge.

"In response to New Yorkers' interest in the safety of their bridges, the State Department of Transportation created a website that provides information on more than 17,000 bridges across the state, enabling everyone to check easily on federal condition classifications and recent bridge inspection dates," Commissioner Astrid Glynn said. "By adding state condition rating information, we are making even more information readily available."

NYSDOT initially posted the site on August 17 in response to heightened public interest following the August 1 collapse of the Interstate 35 bridge in Minneapolis, Minnesota.

The website contains data on all the highway bridges in the state, including their conditions as of August 6, 2007, based upon Federal Highway Administration criteria. Information on the location and owner of each structure, the year it was built or replaced and the date of its last inspection also is provided. The updated website also includes the numerical state condition rating for each bridge and an explanation of the ratings. About 44 percent of New York's highway bridges are owned by NYSDOT, about 50 percent by municipalities and the rest by state and local authorities, commissions and railroads.

NYSDOT makes sure that all the highway bridges in the state are inspected following state and federal mandates. NYSDOT inspects its own highway bridges, as well as highway bridges owned by localities, railroads and commissions that do not collect tolls, ultimately inspecting about 94 percent of the highway bridges in the state. Authorities that collect tolls and commissions are responsible for their own inspections and are required to submit their inspection data. NYSDOT's bridge inspection program exceeds federal requirements and consistently receives high marks in annual Federal Highway Administration management reviews. The state requires all highway bridges to be inspected at least every two years and is one of the few states in the nation that requires bridge inspection teams to be headed by licensed professional engineers who have undergone specific training.

In New York, bridge inspectors are required to evaluate, assign a condition score and document the condition of up to 47 structural elements in addition to general components common to all bridges. The NYSDOT condition rating scale ranges from 1 to 7, with 7 being in new condition and a rating of 5 or greater considered as good condition. A bridge with a condition rating of less than 5 is considered to be deficient, which indicates that the bridge has enough deterioration to require corrective maintenance or rehabilitation to restore the bridge to its fully functional, non-deficient condition. It does not mean that the bridge is unsafe.

In addition to evaluating individual bridge components, NYSDOT also computes an overall New York state condition rating for each bridge by combining the ratings of individual components using a weighted average formula. This formula assigns greater weights to the ratings of the bridge elements having the greatest structural importance and lesser weights for minor structural and non-structural elements. If a bridge has multiple spans, each element common to the spans is rated and the lowest rated element is used in the condition rating formula.

All bridges are analyzed for their capacity to carry vehicular loads. Based upon inspection and load capacity analysis, any bridge deemed unsafe gets closed. There is an established procedure for responding to inspection findings by increasing the inspection frequency, if appropriate, and reporting conditions requiring maintenance or additional review.

New York's condition rating scale is unique and it predates national bridge inspection standards. Other states use different rating scales. However, all states also are required to utilize federal rating scales, which are the basis for annual, state-by-state comparisons of bridge conditions. The federal ratings result from overall average condition assessments of each bridge's three or four major components and do not require the multi-element evaluations mandated by New York State's bridge inspection program.