Maine's Bridges and Minor Spans

As a result of the passage of a new law, the State of Maine has full responsibility for capital improvement and maintenance of 768 minor spans and 1941 bridges*. The state will also pay half of the capital improvement costs for 228 low use/redundant bridges on town ways. There are now 2,937 structures with total or partial state responsibility.

A federal sufficiency rating of 60% or higher indicates that bridges and minor spans are structurally and functionally sufficient and are not likely to need capital improvements for at least 10 years, except for paint or wearing surface work. A chart depicting the condition of Maine’s bridges and minor spans based upon the federal functional class of the roadway is shown below.

The traditional structures (non-steel culverts) typically have a service life of about 80 years while the bridge/ minor span steel culverts normally have a service life of about 50 years. Of the 2,937 structures with state responsibility, there are 379 steel culverts and 2,558 traditional structures.

*Bridges are generally defined as structures with a length equal to or greater than 20 feet. Minor spans are structures between 10 and 20 feet in length. Struts are defined as highway drainage structures that are 5 to 10 feet in length.