Culvert Information Management System - SAGE Journals

Culvert Information Management System Jay N. Meegoda, Thomas M. Juliano, and Chi Tang The New York State Police photograph shown in Figure 1 illustrates the damage to I-88 resulting from a total culvert collapse. Two truck drivers were killed when their rigs fell into the washout caused by heavy rainfall. I-88 was closed in both directions from Schenectady to Syracuse. The washout of all four lanes and center median was a result of a failed 30-ft diameter culvert just beyond the Exit 10 interchange, according to the Albany Times Union (2). Failures of this magnitude typically lead to catastrophic accidents, which may involve the loss of life and property and lead to losses of millions of dollars. Hence, a culvert information system is necessary for timely maintenance of culverts, and such a system can be developed only if remaining service life values of the culverts in the system are known (3). The service life of a culvert may differ from its design life, and it depends largely on the supporting soil, local environment, and corrosive and abrasive properties of the transported fluid and solids. Recognizing the effects of these factors on the deterioration of culverts and taking actions to maintain serviceability conditions can prolong its service life. This recognition and action may prevent premature replacement of culverts and may also prevent costly culvert failures. Currently, underground infrastructure asset accounting is based on a linear depreciation rate and not based on condition assessments of their present state. To ensure long-term durability of culverts and required compliance with federal accounting requirements, state departments of transportation (DOTs) are exploring ways to implement culvert inspection and management programs. This had been a requirement stipulated by the Governmental Accounting Standards Board (GASB), in the Basic Financial Statements and Management’s Discussion and Analysis for State and Local Governments (GASB-34 Standard 1999). GASB-34 requires the governing authorities to declare the present worth of infrastructure assets and to provide useful information on maintenance cost and future replacement cost. It also requires reporting of infrastructure assets as a depreciated cost, scheduled based on the historical cost or a discounted replacement cost. In the GASB-34 Modified Approach, reporting the present cost of preserving eligible infrastructure is allowed in lieu of reporting depreciation or replacement costs. State DOTs have found that funds made available to maintain infrastructure are insufficient in meeting GASB-34 requirements. Hence, the need exists for adopting an optimal strategy that requires accurate information on the present state of infrastructure to be able to predict future performance. The modified approach lays out the requirements toward an efficient culvert maintenance and management system. It requires the state DOTs to

A pilot scale culvert information management system (CIMS) was developed for the New Jersey Department of Transportation to comply with requirements stipulated by the Governmental Accounting Standards Board, GASB-34, and new federal stormwater regulations. The condition states of culverts are used to express the extent of their deterioration and survival probabilities. A financial analysis model was developed on the basis of the remaining value of culverts and the user cost of failures. Different rehabilitation options were discussed, and recommendations were made for deteriorated culverts on the basis of financial analysis. The pilot CIMS can analyze prescribed culvert information and make decisions to inspect, rehabilitate, or replace culverts or to do nothing at project and network levels. At the project level, this is achieved by comparing inspection, rehabilitation, or replacement costs with risks and costs associated with failure. At the network level, the associated costs are optimized to meet annual maintenance budget allocations by prioritizing culverts needing inspection and rehabilitation or replacement. The CIMS has three major computer software components: databases, user interfaces, and functionality modules. Modules include inlet–outlet structures, culvert segments, culvert assessment, and optimization. Users are able to retrieve culvert and inlet–outlet structure physical and financial information and to generate reports vis-à-vis location, road, and milepost for condition state and assets needing immediate repair. The CIMS will also do the following operations: maintain an up-to-date inventory of eligible infrastructure assets; perform maintenance of eligible infrastructure assets for a given budget using a replicable basis of measurement and measurement scale; and summarize results, noting any factors that may influence trends in the information reported.

Culvert pipes play an integral part in transportation infrastructure since they facilitate safe drainage. Typical diameters of culverts that are used range from 6 in. to several feet. Complexity and direct costs of their maintenance grow with the increase in diameter. Indirect costs associated with maintenance, replacement, risk of failure, and highway closure and property damage due to flooding and litigations have also become significant. FHWA discusses operational and serviceability related issues pertaining to deterioration of the structure and its appurtenances, over time (1). A loss of culvert integrity could result in temporary roadway closure and considerable rehabilitation or replacement costs or worse. In addition, the total collapse of a culvert could pose a major safety risk to motorists. Just such a catastrophic failure occurred on the New York State Thruway (I-88) near Unadilla, New York, on June 28, 2006. J. N. Meegoda, Department of Civil and Environmental Engineering; T. M. Juliano, Department of Engineering Technology; and C. Tang, Center for Transportation, New Jersey Institute of Technology, 323 Martin Luther King Boulevard, Newark, NJ 07102. Corresponding author: J. N. Meegoda, [email protected].

• Maintain an up-to-date inventory of eligible infrastructure assets; • Perform condition assessments of eligible infrastructure assets at least every 3 years; • Summarize the results, noting any factors that may influence trends in the information; • Estimate the annual cost of maintenance for infrastructure assets, at or above the established condition level;

Transportation Research Record: Journal of the Transportation Research Board, No. 2108, Transportation Research Board of the National Academies, Washington, D.C., 2009, pp. 3–12. DOI: 10.3141/2108-01

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Transportation Research Record 2108

the system to initiate creation of a database. For culverts, critical sections may be determined based on historical information. During the inspection stage, accuracy of information will be updated. If other sections were found to be critical, then contributing factors are identified to update the database.

Inspection Frequency

FIGURE 1 Collapse of New York State Thruway (I-88) due to culvert failure on June 28, 2006 (photograph courtesy of New York State Police).

• Ensure that the result of the three most recent condition assessments meet or exceed the established condition level; and • Compare the estimated maintenance cost of infrastructure assets at or above the established condition level based on amounts spent during each of the past five reporting periods. Many state and local agencies have yet to implement a culvert management plan based on the Modified GASB Approach. Collecting and interpreting data, to assess the present condition state with respect to deterioration requires accessibility to underground infrastructure, and the ability to perform a proper condition assessment. Hence, the Modified GASB Approach is a justification for implementing a preventive maintenance program, which incorporates user costs associated with culvert failures, such as those due to flooding and roadway collapses, and the ensuing traffic delays and expensive repairs. In many cases, indirect costs can easily exceed direct costs, and ignoring them can lead to less than optimal decisions. A properly developed infrastructure information management system (IIMS) can effectively address the situation.

CULVERT INFORMATION MANAGEMENT SYSTEM This section presents a broad framework needed to develop a culvert information management system (CIMS). It is a substantial enhancement to that proposed by FHWA (4). Included are five major steps: determination of critical sections of the culvert, frequency of inspection, inspection, evaluation of condition state based on inspection, and prediction of the service life based on condition state. A financial model was proposed to make decisions such as repair, rehabilitation, or replacement. A systems approach is proposed where feedback loops update measurements with current information and that also update the existing stored information with the additional (freshly identified) variables to the database for each of the foregoing steps.

Inspection frequency is determined based on physiological or environmental features and should include logical steps. To initiate the process, one could use a mandatory 2-year inspection cycle such as that proposed by FHWA for bridges. Although FHWA recommends that inspections be performed every 3 years, if a comprehensive inspection program were adopted, frequency may vary from 1 to 10 years based on factors such as critical stresses, maximum deformation, hydraulic variables (e.g., flow rates and location), and level of importance of the culvert. Some critical culverts such as corroded and deteriorated or deflected culverts crossing major highways may need to be inspected more frequently, even annually, while other noncritical or newly constructed culverts may be inspected much less frequently. Information gathered should be used to update the database and identify appropriate modifications if deviations are found. Meegoda et al. (5) proposed a rational method to determine the inspection frequency of corrugated steel culvert pipes, which may be expanded to other culvert types.

Inspection This is the most important component of the proposed methodology. Once inspection frequency is determined, culverts should be inspected as stipulated by the schedule and according to the inspection procedures specified. Typical inspection methods include visual including high-resolution digital photography with automated detection (6) and sometimes nondestructive evaluation including ultrasound and X-ray, load testing, and fully instrumented monitoring using strain gauges and fiber optics. On the basis of the information gathered, the database will be continuously updated. This update will affect the information on critical sections as well as inspection frequency. Inspection information from the database should also trigger requests for cleaning and maintenance. Maintenance may include painting, coating, adding protective lining or layers, and in-situ pipe replacement.

Condition State The most challenging task of the proposed methodology is the determination of condition state. Condition states should be consistent and repeatable if used by certified inspectors. To determine the condition state, one should have the historical data for the given culvert and for the given critical section. Long-term inspection data may be used to predict the failure states if no data exist for the failure state. Five condition states based on the Sewer Rehabilitation Manual (7 ) were proposed.

Determination of Critical Sections of the Culvert

Prediction of Remaining Service Life

Deterioration of culverts does not occur uniformly, so one needs to identify the critical sections that will have the greatest deterioration rates. Information from the existing knowledge base is input into

Meegoda et al. used reliability analysis based on a Weibull analysis to relate condition state to remaining service life (8). Figure 2 shows the predicted variation of condition classification with normalized

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Condition Classification (%)

Meegoda, Juliano, and Tang

100 90 80 70 60 50 40 30 20 10 0 0

1 0.2 0.4 0.6 0.8 1.2 1.4 Ratio of Service Life to Expected Design Life (t :td)

1.6

FIGURE 2 Variation of condition classification with ratio of service to expected design life.

life (t:td ) based on reliability analysis with the actual culvert data. Please note that a condition classification value of 0.5 was obtained when the service life was equal to the expected design life, or t:td = 1, where t is the service life and td is the expected design life. Out of more than 100 New Jersey DOT video inspection data files, culverts were selected representing five different material types (steel, cast iron, aluminum, concrete, and brick or clay). Details of those culverts including material type, years in service, and condition classification were used in this analysis. On the basis of Figure 2, one could

TABLE 1 Condition State

Implication

1 2

No visible deterioration Minor surface deterioration less than or equal to 10% (surface rust or freckled rust)

3

Surface deterioration (minor loss of section between 10% and 30%, severe surface rust or freckled rust)

No structural defects Minimal collapse likelihood in short term but potential for further deterioration Collapse unlikely in near future but further deterioration likely

5

a b

Rehabilitation Options and Service Life of the Rehabilitated Pipes Table 1 is a sample in which, based on New Jersey DOT research, a summary was made of recommendations for rehabilitation and

Recommended Techniques Based on Condition State for Corrugated Steel Culverts

Description

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reasonably predict the behavior of most common pipe materials using the Weibull analysis.

Corroded with major surface deterioration (major loss of section greater than 30%, serious or advanced surface rust or freckled rust) Already locally collapsed or almost collapsing (deformed, fractured, and missing sections)

To restore structural capacity. Condition state of new pipe material.

Culvert Size

Culvert Length

Recommended Technique

All All

All All

No action Cleaning and painting

6–12 in. 1–3 ft

All L < 25 ft

Cleaning and painting Cleaning and invert paving or cement mortar lining–precast concrete lining–cured-in-place flexible liner Cleaning and sliplining with polyvinyl chloride liner–fiberglass reinforced cement (FRC) liner– fiberglass reinforced plastic (FRP) liner Cleaning, painting and invert paving– fiberglass reinforced plastic (FRP) liner–cured-in-place flexible liner–precast concrete lining Cleaning and sliplining with PVC pipea FRC pipe–FRP pipea FRA pipea

L > 25 ft

Collapse likely in foreseeable future

>3 ft

All

6–12 in.

All

1–3 ft >3 ft

Collapsed or collapse imminent

All

All

Replace with a new culvert or pipe by excavation or trenchless technology

Improved Condition State

2 2

2

1b 1b 1b

1b

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replacement of pipes that are identified with respect to the five condition states subjected to pipe size and length. The proposed rehabilitation technique would upgrade the condition state, thus enhancing service life. The proposed rehabilitation methods are based on pipe length and size. Pipes that are small to medium size (i.e., 6 to 12 in. and 1 to 3 ft diameter) pose a challenge during inspection and rehabilitation, and they may require the use of robots. The rehabilitation of small to medium sized pipes in Condition State 3 is identified based on pipe length (i.e., whether L < 25 ft or L > 25 ft). This differentiation is made considering the long-term effectiveness of the recommended technique.

Financial Analysis Once the condition states of pipes in the network have been established, the following financial information is required for pipe management decisions, in which the following is known for the ith pipe in the system: • Number of pipes in the network (n where i = 1, 2, . . . , n); • Age or date of installation (Ti ); • Year to be considered (t, where t = 0 for current year, and t = 1 for the next year); • Condition state of some of the pipes based on prior inspection; • Expected life (td or µi ) and variance (σi ) for each pipe; • Cost of installation for each pipe, also assumed to be the same as cost of replacement (Ai,t); • Current value of the pipe after do-nothing–rehabilitation– replacement (Bi,t); • Cost of circuitry (Ci,t); • Cost of inspection for each pipe (Ei,t); • Cost of rehabilitation or replacement for each pipe (Fi,t); • Maximum user cost of failure for each pipe, including new construction cost plus damages associated with such pipe failure (Gi,t); and • Expected user cost for each pipe (Hi,t). The parameters as listed also identify information provided by New Jersey DOT, and the parameters that were used to develop the CIMS. The CIMS uses a zero inflation and a zero discount rate for demonstration purposes. The cost of inspection, rehabilitation and inspection information were extracted from New Jersey DOT bid documents. Assessing the user cost or financial risk associated with failure is the most challenging issue in effective management of any infrastructure. Although one can argue that for culverts, the cost or risk associated with failure is independent of pipe length, it may depend on pipe size; geographic location; whether it is laid along roadway or across roadway; and proximity to critical structures, such as subways, hospitals, and hazardous waste sites. The user cost is usually associated with pipe failures, such as due to flooding and roadway collapses, and the ensuing traffic delays and expensive repairs. Flooding and associated detours and collateral damage are difficult to quantify. Besides, such damage claims can be paid by insurance and thus were not included in the pilot version of the CIMS. Hence, the CIMS developed includes only the roadway collapses and ensuing traffic delays and expensive repairs, which is applicable only for the pipes crossing highways. In estimating the user cost of failure, one should take into account several aspects starting from the probability of


failure of the given pipe, its location, and the consequences of such failures. The New Jersey DOT user cost manual describes the methodology to compute the user cost associated with the traffic delay due to extra travel time and extra travel distance (9). In addition, once the culvert is failed, it should be replaced with a new culvert. Thus, the user cost developed in CIMS (Hi,t) will be the sum of the current cost of installation (Ai,t) plus the cost of detour during replacement of the culvert crossing main roads (Ci,t). Hence, Hi,t = Ai,t + Ci,t × Ui,t where Ui,t is a binary variable (0, 1), such that Ui,t = 1 if the culvert is crossing the road. According to the New Jersey DOT user cost manual, the cost of circuitry or cost of the traffic detour (Ci,t) has two components, that is, circuitry delay and circuitry vehicle operating cost (9). Before one computes the actual road user cost, the delay time through both the work zone and detour (if applicable) must be known. Although the number of vehicles delayed through the work zone or the detour has been determined, the amount of delay can be computed only after knowing the work zone or detour lengths and the times through them. The circuitry delay is computed only when a formal detour route has been established. The delay time through the work zone and through the detour are computed in the same manner. In each case, the delay is determined by subtracting the time it takes to travel through either the work zone or detour when they are present, from the time it takes to travel the same distance when they are not present. The circuitry vehicle operating cost (VOC) is also computed only when a formal detour route has been established. At this point, an overall added travel length per vehicle has been determined. The circuitry VOC is computed by multiplying the number of vehicles that travel the detour, overall added travel length per vehicle, and current VOC cost rate associated with driving the added distance. The example given as follows shows the computation of the cost of circuitry (Ci,t). Estimating Gi,t is another challenge and requires a focused research effort. At this juncture, to develop the framework for analysis and without loss of generality, it is assumed that Gi,t is calculated based on user cost and the probability of failure, that is, Gi,t = pf × Hi,t, where pf is equal to the probability of failure obtained by reliability analysis. To justify a decision of no action, the following should occur:

[B

i, t

− Gi, t ] ≥ 0

(1)

State DOTs are generally responsible in assessing recommendations made by regional and field offices on culvert inspection and rehabilitation or replacement, and those recommendations are to be examined and prioritized while adhering to budgetary allocations. Such decisions should best use the funds allocated for the planning horizon, thus resulting in a net improvement in total network asset value. The following section presents a preliminary model that meets the aforementioned objectives. For a given budget $Zt, the model optimizes the network performance based on the stipulated maintenance policies. These policies are associated with incurred costs. The decisions to be made depend on the state of deterioration of pipe and can be identified as cost of inspection, Ei,t; cost of rehabilitation or replacement, Fi,t; current value of the pipe after do-nothing or rehabilitation or replacement, Bi,t; and cost of no-action leaving it to deteriorate, Gi,t, where t is the year in consideration. Hence, the objective is expressed mathematically as maximize ∑ [ Bi, t − Gi, t X i, t Yi, t ]

(2)


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subject to Z t ≥ ∑ [ Fi, t X i, t (1 − Yi, t ) + Ei, t (1 − X i, t )]

(3)

where Xi,t, Yi,t are binary variables 0 and 1, such that Xi,t = 0 if there is inspection and Yi,t = 0 if there is rehabilitation or replacement.

DEVELOPMENT OF CULVERT INFORMATION SYSTEM With all the aforementioned concepts, a CIMS was developed at New Jersey DOT. The following sections describe the features and functionality of that system. The CIMS consists of two major databases that are used for uploading and manipulating data. The data-uploading database serves as a template that loads the digital culvert inspection data into the system sequentially. User interfaces consist of a main switchboard form, two data review and edit forms, and several functional subforms, shown in Figure 3. The following modules provide functionality of the system.

Data Administration Module The contractor-supplied data are saved on media such as a DVD and videotape. It is required to reorganize the data from the media, upload the data into relevant database tables, and manipulate these loaded records into formats that are suitable for the CIMS application to use. These functions are fulfilled by the data administration module. Current bid documents for culvert inspection projects were modified to require the culvert inspector to provide the inspection data in the specified format to be supplied to New Jersey DOT with the paper report and the inspection video. The data administration module includes three major procedures: 1. Data uploading. In this procedure, valid data records from selected culvert inspector supplied data are uploaded into the CIMS databases. Their related photo files are also copied into a specified image folder and linked to the records. 2. Pipe–manhole links. This procedure generates a table that lists pipe–manhole relationships for projects in the current CIMS database. This relationship table can then be transferred to the straight line dia-

FIGURE 3 Main switchboard form of culvert information management system.

gram program so as to link the endpoints (i.e., inlet–outlet structures) to the correct culvert segments. 3. Database exchanges. This procedure allows users to compact current databases into their backups or retrieves a previously saved database as the current data source of the application for review. Thus, users can save and review their records by projects, by dates, or by their individually defined batch identifiers, so as to reduce the current CIMS application database size.

Inlet–Outlet Structures Module This module gives searchable information about the locations of the pipe endpoints, the inlet–outlet structures, and their conditions. In this module, the digital photos of the culvert inlet and outlet structures are displayed. The inlet–outlet structure data form displays the structure IDs and their attributes, as shown in Figure 4. The user can narrow the scope of a search for particular structure information by three selection criteria: (a) location by road name, (b) location by milepost (1 mi per interval), and (c) the expected inlet–outlet identification number that is close to the rounded-up milepost value.

Culvert Segments Module This module provides searchable information about the pipe location, structure, and condition. In addition, the module enables the user to view the culvert inspection video, re-assess the condition state, and acquire additional pictures to display. The culvert segment data form is shown in Figure 5. Details of the pipe inspections are displayed on the upper part of the form. As with the inlet–outlet structure form, there are three combination boxes on top for the user to narrow down the selection of the particular pipe record. The user selects a location (e.g., road, city, state) and then selects the start-manhole, and finally selects the end-manhole. This form also includes the structure of the pipe, condition of the pipe, and length of the pipe, as well as other information, for example, culvert material type, diameter, thickness, direction of the flow, and drain area.

Culvert Assessment Module A culvert assessment module was developed to perform financial analysis (see Figure 6). This form summarizes information on the pipe’s material type, current condition, treatment cost, and relevant date, for users to make operational decisions, such as the need for inspection or rehabilitation treatment of the culvert. From the current pipe condition values and pipe age, the CIMS will automatically take into account all available data for the selected culvert segment and reference to the culvert treatment policies based on information generated for each culvert material type as shown in Table 1 to propose a treatment option (see Figure 7). If needed, users can make adjustments to the listed cost figures. It has a built-in module to compute the user cost of failure. This module will guide users step by step to estimate the costs used for the assessment process. By combining the risk of failure value with the maximum user cost of failure, the system computes the estimated cost of failure and compares that value with the actual value of the culvert as shown by Equation 1 to lists of all suitable treatment techniques for users to select and compares their corresponding expenses. Based on the comparison, CIMS

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FIGURE 4

FIGURE 5

Inlet–outlet structure data form.

Culvert segment data form.


FIGURE 6

Culvert assessment form.

FIGURE 7

Treatment cost justification form.

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will recommend or deny the user selection and remind the user to check existing data sets.

Optimization Module After determining the treatment techniques for each culvert and pipe segment under consideration, the user can define project groups and search the optimal or near optimal solutions for a given budget allocation. This is done by the CIMS optimization module (Figure 8). The system evaluates the input data set and summarizes its major attributes; for example, how many culvert segments are in the network, what is the total capital required by these segments, and how many pre-fixed segments as well as the minimum required budget for these pre-fixed culverts. The system provides two methods to solve Equations 2 and 3 using the 0-1 implicit enumeration algorithm to find real optimal solution or a heuristic procedure. The 0-1 implicit enumeration algorithm enumerates all possible combinations of the decision variables and compares their resulting objective function values to determine the real optimal solution. However, the heuristic procedure sorts the selected culvert jobs by their capital requirements and then tries to incrementally add the most costly ones without breaking the budget limit. The reason for having two algorithms is that the real-optimal solution for the integer program problem has 2N computational complexity. Although the objective function and budget constraint are both simple linear additions, it may take a long time to evaluate all possible combinations when the number of culverts requiring decision (N) is

FIGURE 8

Network selection.

large. Therefore, it is recommended that the heuristic be used when N > 25. The heuristic covers the more costly segments first and then the smaller ones until the available budget runs are exhausted. Figure 9 displays a sample solution report. The report layout and its contents may be modified to meet customer requirements.

SUGGESTIONS FOR FUTURE RESEARCH This project is a limited scope demonstration project of implementing the CIMS. Several aspects need further research and implementation, listed as follows: 1. The proposed CIMS was developed in association with the New Jersey DOT straight line diagram database. This should be upgraded to a database that is based on a geographic information system. 2. The CIMS developed in this demonstration project contains only the culverts inspected to date. To perform systemwide optimization, one needs all the information on all of the culverts in the state of New Jersey. Until that information is available, the proposed system is unable to perform a complete systemwide optimization to comply with GASB-34 requirements. Hence, the future research should include the development of this component. 3. The proposed CIMS only considers in-kind replacement, which is not always possible. Therefore, the system should be upgraded to include replacement with different types of culverts.


FIGURE 9

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Sample solution report.

4. Most of the culverts are not inspected during the current year. Hence, a mechanism should be developed to predict the current condition state based on the past condition state. Doing so involves substantial mathematical analysis, and hence it is proposed to be included in future developments. 5. On the basis of the current New Jersey DOT administrative structure, capital investments and maintenance expenditures occur in two separate departments. However, the program assumes funds for both come from one source. Thus, the DOT should consider changing its administrative structure or, in future programs, it should split funds to perform DOT optimizations.

SUMMARY AND CONCLUSIONS The following are the conclusions of this research: 1. Information on management systems for underground infrastructure such as pipes and culverts is limited. Earlier works have found that both structural and serviceability conditions need to be considered when formulating a management strategy for a storm water network. 2. In this research, culvert deterioration is defined based on the condition states, and the assumption that life added through rehabilitation results in an upgrade of the condition state. 3. The reliability of the culvert depends on the probability that it will operate for a specific period of time, for example, its design life

under its design conditions without a failure. The Weibull distribution was chosen to model the reliability of the culvert. 4. A model to perform financial analysis was developed and implemented in the CIMS. 5. The CIMS optimizes the allocation of annual maintenance budgets by determining the culverts needing inspection and rehabilitation or replacement. In addition, the CIMS can be used to make project-level decisions to inspect, rehabilitate or replace, or do nothing. 6. A pilot-scale CIMS was developed, tested, and implemented for New Jersey DOT. The CIMS will serve as a vehicle for evaluating culverts, facilitating computation of their present worth, and comparing the present costs of preserving them. Benefits of the CIMS will include longterm savings that should accrue from adopting optimized preventive maintenance strategies.

ACKNOWLEDGMENTS This research was sponsored by a research contract from the New Jersey Department of Transportation. The authors acknowledge the efforts of Robert Sasor of New Jersey DOT and the contributions of Camille Crichton-Sumners, Anthony Gould, Donald Perry, and Alkesh Desai of New Jersey DOT; Hadi Pezeshki of FHWA; and Nicholas Vitillo, retired manager of the Bureau of Research at New Jersey DOT.

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REFERENCES 1. Culvert Repair Practices Manual, Vols. I and II. RD-94-096/FHWA. RD-94-089. FHWA, U.S. Department of Transportation, 1995. 2. Pacenza, M. State Warned Worst Isn’t Over: Damage Spreads Amid New Flooding. Albany Times Union, June 29, 2006. www.timesunion.com/ AspStories/story.asp?storyID=495707&category=REGIONOTHER& BCCode=HOME&newsdate=6/29/2006. 3. Meegoda, J. N., T. M. Juliano, P. Ratnaweera, and L. Abdel-Malek. Framework for Inspection, Maintenance and Replacement of Corrugated Steel Culvert Pipes. In Transportation Research Record: Journal of the Transportation Research Board, No. 1911, Transportation Research Board of the National Academies, Washington, D.C., 2005, pp. 22–30. 4. Culvert Management Systems—Alabama, Maryland, Minnesota, and Shelby County. Transportation Asset Management Case Studies. FHWA, U.S. Department of Transportation, 2003. 5. Meegoda, J. N., T. M. Juliano, M. G. Ayoola, and S. Dhar. Inspection, Cleaning, Condition Assessment, and Prediction of Remaining Service Life of Corrugated Steel Culvert Pipes. Presented at 83rd Annual Meeting of the Transportation Research Board of the National Academies, Washington, D.C., 2004.


6. Meegoda, J. N., T. M. Juliano, and A. Banerjee. Framework for Automatic Condition Assessment of Culverts. In Transportation Research Record: Journal of the Transportation Research Board, No. 1948, Transportation Research Board of the National Academies, Washington, D.C., 2006, pp. 26–34. 7. Sewerage Rehabilitation Manual, 4th ed. Vol. I, Rehabilitation Planning. WRC, Blagrove, Swindon, Wiltshire, United Kingdom, 2001. 8. Meegoda, J. N., T. M. Juliano, and S. Wadhawan. Estimation of the Remaining Service Life of Culverts. Presented at 87th Annual Meeting of the Transportation Research Board of the National Academies, Washington, D.C., 2008. 9. User Cost Manual. New Jersey Department of Transportation, Trenton, 2003. The contents of this paper reflect the views of authors, who are responsible for the facts and the accuracy of the information. The contents do not necessarily reflect the views or policies of NJIT, NJDOT, or FHWA. This paper does not constitute a standard, specification, or regulation. The Maintenance and Operations Management Committee sponsored publication of this paper.