Bridge types

Long beams (girders) placed parallel to traffic that carry the deck. The most common bridge type in the United States.

Poor: 8.2% · Average age: 45.6 years

A pipe or box structure carrying water beneath the roadway. Culverts over 20 feet long are counted as bridges.

Poor: 2.4% · Average age: 47.9 years

A solid, flat concrete slab that acts as both the supporting structure and the roadway surface. Common for short crossings.

Poor: 6.0% · Average age: 47.7 years

Hollow rectangular concrete beams placed side by side so their top flanges form the deck.

Poor: 5.1% · Average age: 38.6 years

T-shaped concrete beams cast with the deck, popular from the 1920s through the 1960s.

Poor: 8.4% · Average age: 61.4 years

C-shaped (channel) concrete beams placed side by side, common on short county road bridges.

Poor: 11.7% · Average age: 42.4 years

One or a few hollow box girders spaced apart beneath the deck, often used for longer spans and curved alignments.

Poor: 1.3% · Average age: 32.1 years

A truss that rises above the roadway, with traffic passing through the structure.

Poor: 39.0% · Average age: 82.2 years

An arch below the deck, carrying load in compression down to the abutments.

Poor: 12.9% · Average age: 84.3 years

A rigid frame where the deck and the supporting legs are a single continuous structure.

Poor: 2.4% · Average age: 45.3 years

Main girders along the bridge with transverse floorbeams carrying the deck, typical of larger steel bridges.

Poor: 22.7% · Average age: 69 years

A structure type not covered by the standard categories.

Poor: 10.1% · Average age: 36.6 years

A movable span that tilts upward on a pivot, like a drawbridge.

Poor: 21.9% · Average age: 64.8 years

A box girder built from precast or cast-in-place segments joined together.

Poor: 1.7% · Average age: 26.5 years

A truss that sits below the roadway, so traffic rides on top of the structure.

Poor: 19.6% · Average age: 74.9 years

An arch that rises above the deck, with the roadway hung from or passing through the arch.

Poor: 10.6% · Average age: 62.9 years

A movable span that is raised vertically between towers to let vessels pass.

Poor: 15.5% · Average age: 58.3 years

A movable span that rotates horizontally around a central pier.

Poor: 29.2% · Average age: 71.1 years

A deck hung from cables draped between towers. Used for the longest spans.

Poor: 20.8% · Average age: 86.2 years

A deck supported by cables running directly to one or more towers (cable-stayed).

Poor: 2.9% · Average age: 22.2 years

A structure combining more than one main structure type.

Poor: 13.0% · Average age: 74 years

A stiffened steel plate deck that acts together with the supporting girders, used on long-span bridges.

Poor: 29.4% · Average age: 45.3 years