Bridge Management Systems The number of socially and economically important struc- tures grot's ceaselessly, while maintenance budgets seem only to shrink. Thus, infrastructure owners, or their agents, are in dire need of tools to support decision-making. Over the years, some agencies have attempted to systematize data on structures using classical paper filing schemes to contain condensed structural data that is regular/v needed for the ad- ministration and preservation of structures. This can already he regarded as Management System. Today, the sheer volume of data and the growing sophistica- tion of decision-making models have made the use of a com- puter indispensable, to a point where the term "Management System" directly refers to a computer program. Modern sys- tems not only document the past, they also extrapolate the future condition of structures and evaluate their preservation needs. In the future. management systems will contain data Bojidar S. Yanev, Civil Eng. Dept of Transportation. New York. NY. USA on structural systems, structural details, plans, i. e., all in for- mation for the successful planning of preservation actions. Furthermore, the' will make it possible to track the per for- mance of structural details, or even entire structures, in a systematic manner. Wit/i this two-part Bridge Management Systems series, SE! allows readers to track these exciting developments. Al- though the original goal ttas to cover all types of structures, the series reduced itself to bridge management systems, which are undoubtedly more mature than systems for other struc- tural types. We in vite engineers involved with management systems for structures other than bridges to contact the Publi- cations Com,nittee as a first step toward informing SEJ's readers about their ;t'ork. Rade Hajdin Series Coordinator Introduction There are 280898 state and interstate and 309 142 local bridges in the United States. 25% of the former and 36% of the latter, or 31% of the total 590040. are considered substandard [1]. In recognition of this state of the national infrastructure, Congress passed the I ntermodal Surface Transportation Efficiency Act (ISTEA) in 1991. As a result, bridge management became a mandated, or at least recommended, part of the activities of all state depart- ments of transportation. Over a period of several ears, the bridge manage- ment program package PONTIS. sponsored by the Federal Highway Administration (FHWA). was devel- oped under the guidance of a task force representing the American As- sociation of State Highway and Trans- portation Officials (AASHTO). and adopted for implementation by a ma- jority of states. A number of other states, including New York. Pennsvlva- nia and Indiana. developed their own bridge management programs. Peer-reviewed by international 'f' experts and accepted by the IABSE Publications Committee A 1993 FHWA executive order man- dated that benefits and costs of infra- structure investment be measured and appropriately discounted over the full life-cycle of the project. The current National Cooperative Highway Re- search Program (NCHRP) Project 12-43 is developing an algorithm and software for life-cycle costs analysis. Yet most bridge management deci- sions are subject to important con- straints beyond the immediate sphere of bridges. Consequently, actual bridge management is not advancing at the rate with which various bridge man- agement systems are developing. Fu- ture progress in bridge management will require an interdisciplinary effort engaging a broad range of expertise beyond that of structural mechanics. If they are to manage their bridges, engi- neers of the future will have to develop and master a branch of economics suit- able to their needs. In the meantime. although the techni- cal and analytical aspects of bridge management have advanced, major problems persist. The following key needs have been identified: — data sets that qualitatively and quantitatively define structural con- dition — deterioration models for accurate condition and reliability prognoses — preservation actions and costs cor- related with condition states. To illustrate the current status of the above issues on the level of practical application, the 847 bridges managed by the DOT of the City of New York are examined [2]. This article presents the views of the author and not those of any agency or organization. Development of Bridge Management in New York City Management Structure Some of the Citv's most famous and largest bridges, such as the George Washington (1931). Bayonne (1931). Triboro (1936). Henry Hudson (1936). Whitestone (1939). Throg's Neck (1961) and Verrazano (1964) are man- aged by the Port and Triboro Authori- ties, who charge tolls for crossing ei- ther in one or in both directions. The Hell Gate (1912) is a railroad bridge operated by Amtrak. Approximately 600 mostly post-World War Two high- wa bridges are the responsibility of New York State as part of the Inter- state network. Several thousand spans. mostly steel structures, support elevat- ed sections of the Cit subway system. Another 770 bridges with 4753 spans are managed by the City of New York. Structural Engineering International 3/98 Reports 211 Bridge Management for New York City