Defining Bridge Preservation by Action Type

There has been progressive interest from FHWA and state departments of transportation (DOTs) in considering bridge preservation an essential part of a comprehensive bridge program. The available definitions of bridge preservation give a conceptual overview; they do not identify specific bridge preservation actions. The objective of this study was to come up with a comprehensive list of bridge actions, as identified by bridge experts, and to identify the specific actions that the experts defined as preservation. A comprehensive list of 94 bridge actions was developed with input from 12 DOTs. Through an online survey, bridge experts were asked to classify each bridge action as operations, maintenance, preservation, rehabilitation, improvement, or replacement. Although the level of consensus in the final classification of the bridge actions varied, 64 actions were assigned to the same category by more than 50% of the respondents. The authors used the simple majority to determine an action's classification but reported the percentages for all categories, with the intention of presenting alternative criteria and related levels of response to the readers. Fifty-two percent of the actions were classified as maintenance; 15% of the actions were classified as preservation. Examples of bridge preservation actions included the addition of wearing surfaces to protect decks, painting to protect steel, and the mitigation of scour to protect the bridge. From the results, it appeared that industry professionals used “maintenance” and “preservation” almost interchangeably. A comparison between the results of this research and published text definitions of preservation found that the text definitions were very broad and included actions considered by the participants in this research to be maintenance, preservation, or rehabilitation.