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59 the expected damage state of the bridge. The travel delays tion assets against terrorist threats, including bridges, tunnels, resulting from closure of damaged bridges are calculated using roadways, interchanges, tollhouses, and roadside infrastructure origin-destination (O-D) tables, coupled with network analy- (e.g., signs, barriers, sensors). It provides a six-step process sis of the pre-earthquake scenario with a base transportation for conducting a vulnerability assessment. Key aspects of the network and the post-earthquake scenario with a modified guide include: transportation network. The consequence of earthquakes on the transportation network is evaluated for a magnitude 7.0 Reliance of the organization to organize and sustain a multi- earthquake scenario in California. The information for bridge disciplinary team ready to identify critical assets, perform inventory and the highway transportation network was vulnerability assessments, and subjectively identify costs and obtained from transportation agencies for this study. The study effectiveness of countermeasures. reports that liquefaction damage is the largest contributor to the Guidance on selecting critical assets and subjectively assign- repair cost which is used as a measure of the loss from damage. ing "asset criticality" scores over a number of asset factors and their subsequent aggregation to determine a criticality System Risk Curves: Probabilistic Performance Scenarios factor for each asset. for Highway Networks Subject to Earthquake Damage Guidance on subjectively assessing "asset vulnerability" (12). The authors develop methods for evaluating the per- scores over a number of factors and their subsequent aggre- formance of highway systems subjected to severe earthquake gation to determine a vulnerability factor for each asset. impacts. In this study, the total transportation network delay is Guidance on combining and analyzing the criticality and estimated with user-equilibrium network analysis methods to vulnerability assessments to determine countermeasure evaluate the network system performance due to seismic action. induced damage. The bridge damage and highway network Guidance on countermeasures spanning the capital, main- link damage is evaluated by means of a damage index with tenance and operational areas, countermeasure packaging, Monte Carlo simulation techniques and bridge fragility curves. and first-order estimation of costs for countermeasures. The fragility curves for individual bridges are developed on Guidance on reviewing operational and security planning. the basis of empirical damage data and dynamic analysis performed on bridge structures. These curves are used to gen- The guide relies heavily on experience, expertise, and erate network damage states for various earthquake scenarios resource commitment. There is very little automation of the by means of Monte Carlo simulation. To test the approach process and the factors chosen are subjective to a point where changes in system performance in different scenarios are mea- different teams looking at the same asset or vulnerability could sured in terms of additional total network delay for a set of potentially come up with different scores and mitigation pri- sample scenarios. The final result of these efforts is a transpor- orities. The Guide also stops short of proposing a methodology tation system risk curve, which shows the annual probability of to compute/impute the consequences of extreme events. exceedance and the hazard-consistent probability for different levels of network delay. NCHRP Project 20-59: Guide to Risk Management of Multimodal Transportation Infrastructure (2). This report Multi-Objective Optimization for Bridge Management seeks to improve upon the concepts presented in the 2002 Systems (13). Appendix B of this report details an approach AASHTO Guide, and expand the applicability of the proce- to calculating a vulnerability rating for a structure for scour, dures developed to all intentional, unintentional, and natural fatigue, seismic, and other vulnerabilities. This approach is in hazards and all modes of transportation, not just highways. It turn based largely upon work performed by the New York makes significant proposals in formalizing the risk manage- State Department of Transportation. The vulnerability scor- ment process, but it consciously avoids consequence modeling ing approach described here provides a thresholding approach benefit/cost analysis, return on investment calculations, and/or for assessing structures risk that can be used in conjunction other economic analysis of risk consequences and mitigation with the risk assessment approach described in Section 3. measures. Further, event probability is not fully tied into risk Note that other portions of this report are also relevant, and calculation for all threats/hazards. described further in the review of data and analytical tools. A.2 Asset Data and Analytical Tools AASHTO and NCHRP Guides to Risk Management Data 2002 AASHTO Guide to Highway Vulnerability Assess- Cambridge Systematics, U.S. Domestic Scan Program: ment (1). This document, developed in the immediate Best Practices in Transportation Asset Management (14). aftermath of the 9/11 attack, focuses on providing high level This scan report identifies best practice examples of the guidance for vulnerability assessment of highway transporta- application of asset management principles and practice in

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60 U.S. transportation agencies. The scan participants included and barrier management including the proposed data and FHWA officials, representatives from state transportation procedures specific to walls and barriers and recommendation agencies in Michigan, North Carolina, Ohio, Oregon, and on inspection practice and intervals. Vermont, a university professor in transportation engineering and planning, and a consultant support staff. Use of Highway Maintenance Management Systems in State Highway Agencies (21). This paper details surveys of Highway Performance Monitoring System Reassessment 29 state highway agencies on the state-of-the-practice in 2010 (15). The report summarizes the HPMS 2010+ MMS. It shows there is considerable variation between agen- reassessment recommendations, including stakeholder input, cies in the data collected in their MMS and the state of MMS proposed recommendations, and impacts of the reassessment. implementation. The reassessment is intended to address current and future business needs, address new data requirements in transporta- XML Schemas for Exchange of Transportation Data tion reauthorization legislation, and update HPMS to take (22). For the NCHRP 20-64 Project detailed in this report, a advantage of technological improvements. research team developed TransXML--a family of broadly accepted public domain eXtensible Markup Language (XML) Managing Selected Transportation Assets: Signals, schemas for exchange of transportation data. The following Lighting, Signs, Pavement Markings, Culverts, and Side- pilot business areas were selected as the focus of the study: walks (16). This study examines the state-of-the-practice for Survey/Road Design; Transportation Construction/Materials; managing transportation infrastructure assets other than Highway Bridge Structures; and Transportation Safety. The pavements and bridges, including traffic signals, lighting, report discusses the possible benefits by adopting and expand- signs, pavement markings, drainage culverts, and sidewalks. A ing TransXML, and highlights efforts designed to help ensure key finding is that the amount of data and manner collected its success. varies significantly for these assets between different agencies. Asset Management Data Collection Guide (23). This Culvert Management Systems: Alabama, Maryland, guide was prepared by a joint committee of AASHTO, the Minnesota, and Shelby County (17). This report provides Associated General Contractors of America (AGC) and the details about the culvert management data and practices used American Road and Transportation Builders Association in four jurisdictions, and provides guidance for agencies seek- (ARTBA). It reviews asset management concepts, discusses ing to improve their culvert management approach. current data collection practices, and presents a set of criteria for determining what data to collect. Also, this guide recom- Highway and Rail Transit Tunnel Inspection Manual mends inventory and condition data items that should be col- (18). This manual was developed by FHWA and the Federal lected for: Transit Administration (FTA). It provides specific information for the inspection of both highway and rail transit tunnels. The Drainage assets, including culverts, ditches, drop inlets, goal of the manual is to provide uniformity and consistency in catch basins, drains, curbs, and sidewalks; assessing the condition of the various tunnel components and Roadside assets, including grass, slopes, and fences; to present good maintenance and rehabilitation practices. Pavement assets, including pavement and shoulders; and Traffic assets, including signs, pavement markings, pave- Guidelines for the Installation, Maintenance, and Repair ment markers, guardrail, guardrail treatments, and traffic of Structural Supports for Highway Signs, Luminaries, and barriers. Traffic Signals (19). This document is designed to provide guidance for the installation, inspection, maintenance, and Analytical Tools repair of structural supports for highway signs, luminaries, and traffic signals. It recommends using an element-level A comprehensive review of asset management tools was approach for inspecting these structures, similar to that used recently performed for NCHRP Project 20-57 and docu- for bridges using the AASHTO Pontis BMS. mented in NCHRP Report 545 (23). The research team used the materials gathered through the NCHRP 20-57 project as Colorado DOT, Feasibility of a Management System for a starting point. This information was supplemented with a Retaining Walls and Sound Barriers (20). This report review of the literature published since the completion of makes the case that the management systems for retaining NCHRP Project 20-57 and additional best practice examples walls and sound barriers are feasible and can be modeled on and information on data resources. Also, the research team existing systems for bridge management such as AASHTO's reviewed materials from other relevant NCHRP efforts, and Pontis BMS. It presents the tasks for full development of wall materials available on systems developed or distributed by

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61 AASHTO, FHWA and other Federal agencies. The review was for supporting pavement management outweigh the costs, performed to help answer two questions: but relatively few DOTs are using GIS as part of their pave- ment management decision process. What asset data and analytical tools are in use in the United States and/or international agencies that could help sup- Multi-Objective Optimization for Bridge Management port the Interstate Asset Management Framework; and Systems (13). This report reviews approaches to multi- What data and analytical tools are available in the public objective optimization, and prototype application of a domain for immediate implementation during the frame- heuristic approach to BMS data. It recommends adapting the work pilot? incremental benefit cost (IBC) approach already used for sim- ulation models in many management systems for use in a The following is a summary of the materials reviewed. multi-objective approach, expanding this into an incremental utility cost (IUC) approach to factor in additional objectives. Analytical Tools for Asset Management (24). This report The report also describes two spreadsheet tools developed details the set of analytical tools available as of 2005 and through the project, the Multi-Objective Optimization System describes two new tools developed through the NCHRP 20-57 (MOOS) bridge-level and network-level models. Although Project: AssetManager NT for network-level asset analysis and MOOS is intended to integrate programmatic risks with risks of AssetManager PT for project-level analysis. In establishing the system failure, as these concepts are described in Section 3, it needs for a new analytical tool, the NCHRP 20-57 research team can be used to prioritize risks of system failure consistent with reviewed the available literature, performed detailed interviews the approach detailed in Section 3. of 10 transportation agencies, and prepared detailed profiles of AASHTO Guidelines for Maintenance Management 11 tools available in the public domain, including: Systems (27). This document describes MMS functionality at a general level and identifies the components of a compre- Highway Economics Requirements System State Version hensive MMS that agencies should consider in terms of their (HERS-ST); approach to maintenance management and their operating Highway Development and Management Tool (HDM-4); environment. These components include: planning; pro- Surface Transportation Efficiency Analysis Model (STEAM); gramming and budgeting; resource management; scheduling; Intelligent Transportation Systems (ITS) Deployment monitoring and evaluation; and maintenance support and Analysis System (IDAS); administration. Pavement LCCA Tool, now titled RealCost; EAROMAR (Economic Analysis of Roadway Occupancy Disruption Impact Estimating Tool--Transportation for Maintenance and Rehabilitation); (DIETT)--A Tool for Prioritizing High-Value Transporta- MicroBENCOST, since superseded by BCA.NET; tion Choke Points (28). This report details a tool developed StratBENCOST; to prioritize risks to transportation choke points (TCP) such as Transportation Decision Analysis Software (TransDec); bridges and tunnels. The tool includes a Microsoft Access National Bridge Investment Analysis System; and application for filtering a set of TCPs. The Access application Bridge Life Cycle Cost Analysis (BLCCA) Tool, detailed in exports data to an Excel spreadsheet which is used to perform NCHRP Report 483: Bridge Life-Cycle Cost Analysis (25). the prioritization. The example provided with the study shows the example prioritization of bridges based on NBI data and Further, the report details what tools are available and/or in additional parameters used to characterize the economic value use, discusses the gaps in existing tools, and details the need for of freight traffic utilizing the TCP. DIETT is designed to work new functionality, both in the AssetManager tools developed in conjunction with the Consequences Assessment Tool Set through the project and in other analytical tools. (CATS) developed by Science Applications International Corp. (SAIC). Pavement Management Applications Using Geographic Information Systems (26). This synthesis describes Prototype Software for an Environmental Information approaches to integrating PMS and Geographic Informa- Management and Decision Support System (29). This tion Systems (GIS). It reports that approximately half of details data sources and analytical tools used by transporta- state DOTs use global positioning systems (GPS) as part of tion agencies for environmental management. This reference their data collection process, though data collected by GPS describes the prototype environmental information manage- present issues because of the lack of compatibility with his- ment system developed through NCHRP Project 25-23(2) for torical data and interoperability with existing systems. The storing environmental management data for supporting synthesis concludes that the benefits of implementing a GIS long-range planning, project development and maintenance.