Chapter 7: Bridge ProgrammingAnchor: #i998827
Section 1: Basis for Bridge Rehabilitation or ReplacementAnchor: #i1006814
Some bridges on public highways in Texas are considered structurally deficient or functionally obsolete. The terms functionally obsolete (FO) and structurally deficient (SD) are general terms used by the FHWA to classify bridges for eligibility to receive federal funding from the Highway Bridge Program.Anchor: #i1028330
The term "structurally deficient" is used by the Federal Highway Administration to designate bridges eligible for federal funding. A structurally deficient bridge is one with routine maintenance concerns that do not pose a safety risk or one that is frequently flooded. To remain open to traffic, structurally deficient bridges are often posted with reduced weight limits that restrict the gross weight of vehicles using the bridges. A structurally deficient bridge should not be confused with an unsafe bridge. Through regular inspection, TxDOT identifies unsafe conditions and closes unsafe bridges. A structurally deficient bridge, when open to traffic, typically requires significant maintenance and repair to remain in service and eventual rehabilitation or replacement to address deficiencies. To remain in service, structurally deficient bridges are often posted with weight limits to restrict the gross weight of vehicles to less than the maximum weight allowed by Texas law (80,000 pounds).Anchor: #i1028377
The term "functionally obsolete" is another FHWA term for classifying bridge eligibility for federal funding. A bridge is classified by the FHWA as functionally obsolete if it fails to meet its design criteria either by its deck geometry, its load-carrying capacity, its vertical or horizontal clearances, or the approach roadway alignment to the bridge.Anchor: #i1028423
Methods have been developed to allocate funds and prioritize the rehabilitation or replacement of structurally deficient or functionally obsolete bridges. These methods are described below. Further information on the subject can be found in the Bridge Project Development Manual.