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1.
This paper presents guidelines for implementing the construction warranty contracting method in the highway construction industry. A logical, step-by-step method for effectively applying the warranty contracting program for use in the highway construction industry is developed. Relevant issues that may present obstacles to the implementation are addressed, while the best practices, compiled from an evaluation of the current industry’s state-of-the-art practices, will assist an interested state highway agency in creating a warranty specification. In performing this research, the current use of warranty specifications among state highway agencies was examined, and an in-depth case study of the Wisconsin Department of Transportation’s warranty program was conducted.  相似文献   

2.
In recent years, the state departments of transportation have implemented a number of highway rehabilitation projects across the country. These projects differ fundamentally from new highway projects in that they require an uninterrupted flow of traffic throughout both the duration and geometric length of the project. Synchronization of traffic closure with the construction activities is crucial in such projects to avoid the traffic conflicts and prevent idle time for equipment and labor. Although most highway rehabilitation projects involve predominantly linear activities, the techniques of linear scheduling are not readily applicable to highway rehabilitation projects due to the conflict between the workzone and traffic flow. This paper documents the development of a traffic closure integrated linear schedule (TCILS) that addresses both traffic closure and work progress issues. The TCILS generates a single schedule for both the construction activities and the associated traffic closures. Visual and graphical features are also applied in the system, which makes it particularly applicable for highway rehabilitation projects. An actual concrete pavement rehabilitation project using the TCILS is presented as a sample of application. The findings from the sample project, although they are limited, show that the TCILS can be applied to an actual project. With recommended future development, the system is believed to be beneficial for both construction practitioners and academics.  相似文献   

3.
Due to the public expectation of better road performance accompanied by economic development and population growth over the past decades, state highway agencies have been under intense pressure for continuous improvement in the quality and cost efficiency of transportation projects. To meet these challenges, state highway agencies must seek innovative approaches to deliver highway projects, including outsourcing some of the agency’s functions and shifting maintenance responsibilities to contractors. Many states have implemented alternative contracting methods in project programming and execution to provide lasting and functional roadways at the optimum life-cycle cost to the public. The performance warranty is one of the innovative practices that has been declared operational by the Federal Highway Administration since 1996. Use of warranties in some states has required changes to state legislation and agency regulations. This paper discusses the laws and regulations needed to successfully incorporate performance warranties into current contracting practices and avoid litigation. The state of Alabama is used as an example of a state considering the use of performance warranties. Proposals for laws and regulations will be outlined.  相似文献   

4.
This paper investigates the likelihood of occurrence and quantifies the magnitude and rate of discrepancies in highway project final costs with respect to their contract award amounts. Using data from Indiana, we develop a multistep econometric approach that can be used to estimate the effects of factors associated with the contract bidding process, project type, and the project physical environment on cost discrepancies in highway contracts. Estimation findings indicate that for a given project type and project year, contracts of larger size or longer duration are generally more likely to incur cost overruns. In addition, for contracts that incur cost overruns, the cost overrun rate decreases nonlinearly with increasing contract size up to a certain point after which the cost overrun rate increases with increasing contract size. Our approach allows for the possibility that cost overrun amounts are not linearly related to contract award amounts (contract size), and shows that greater analytical flexibility needs to be incorporated into any investigation of contract cost overruns. Agencies interested in improving their financial forecasts can replicate our proposed methodology using local contract data.  相似文献   

5.
The objective of this study was to reveal the trend in highway construction costs following Hurricanes Katrina and Rita in Louisiana. The means of measuring highway construction cost was the Louisiana Highway Construction Index, an index made up of the cost of labor, equipment, and six major materials used in highway construction. Data from projects let by the Louisiana Department of Transportation and Development from the second quarter of 2003 to the second quarter of 2007 were used to track the change in construction costs. Index values from hurricane-impacted areas (GO Zones) were compared with those in Non-GO Zones. The indices revealed that two quarters after Hurricanes Katrina and Rita, the highway construction cost jumped about 20% statewide and 51% in GO Zone. Two years after the hurricanes, the cost has stabilized to around 30% increase over the pre-Katrina and Rita period. This study provides valuable information for the state agency to estimate cost escalation in ongoing projects and to estimate future disaster response to highway construction costs.  相似文献   

6.
In this study, we focus on road construction and analyze technology development projects. Based on the business strategy literature and literature on technology policy, we test the relative importance of a firm’s strategies and government as a buyer and champion. Our empirical findings stress the value of government championing behavior. Our results show that in road construction, championing behavior is more important than public technology procurement for project performance. The results even suggest that government championship is more important than a firm’s strategic orientation.  相似文献   

7.
The utilization of nighttime work in highway construction and rehabilitation projects has been increasing in recent years throughout the United States. In this type of projects, construction planners are required to develop and submit a lighting plan that provides: (1) adequate illuminance levels for all planned nighttime construction tasks; (2) reasonable uniformity of light distribution in the work area, and (3) acceptable glare levels to both road users and construction workers. In order to support construction planners in this vital and challenging task, this paper presents a lighting design model, named CONLIGHT, which is capable of considering the specific requirements of nighttime highway construction operations. The model is developed to enable construction planners to evaluate the performance of various lighting plans and select a practical design that complies with all lighting requirements for the nighttime work being planned. An application example is analyzed to illustrate the use of the model and demonstrate its accuracy and capabilities in generating practical lighting plans for nighttime construction and rehabilitation projects.  相似文献   

8.
This paper presents the development of a practical framework for identifying the lighting requirements for nighttime highway construction activities. The framework is named Construction Visual Requirements, “CONVISUAL,” and is designed to consider and quantify the varying lighting needs for different visual and construction tasks. The framework is developed using an original and interdisciplinary approach that integrates concepts and models from construction engineering and vision science to ensure the provision of adequate lighting conditions on site that enable workers to properly see and perform their tasks safely and with satisfactory quality. CONVISUAL determines the required illuminance level for each construction activity based on its required visual tasks and the visual capacity of construction workers. A prototype of CONVISUAL framework is implemented to illustrate its unique capabilities of (1) providing a deeper understanding of the visual requirements of nighttime construction activities; (2) specifying the required illuminance levels in a scientific and systematic approach; and (3) delivering a rational justification for the specified illuminance levels.  相似文献   

9.
Time-Cost-Quality Trade-Off Analysis for Highway Construction   总被引:2,自引:0,他引:2  
Many departments of transportation have recently started to utilize innovative contracting methods that provide new incentives for improving construction quality. These emerging contracts place an increasing pressure on decision makers in the construction industry to search for an optimal resource utilization plan that minimizes construction cost and time while maximizing its quality. This paper presents a multiobjective optimization model that supports decision makers in performing this challenging task. The model is designed to transform the traditional two-dimensional time-cost tradeoff analysis to an advanced three-dimensional time-cost-quality trade-off analysis. The model is developed as a multiobjective genetic algorithm to provide the capability of quantifying and considering quality in construction optimization. An application example is analyzed to illustrate the use of the model and demonstrate its capabilities in generating and visualizing optimal tradeoffs among construction time, cost, and quality.  相似文献   

10.
This paper presents a decision support system for optimizing temporary lighting arrangements in nighttime highway construction projects. The system is developed as a multiobjective genetic algorithm that is capable of: (1) maximizing average illuminance on construction sites; (2) maximizing lighting uniformity in the work zone; (3) minimizing glare to workers and road users; and (4) minimizing lighting costs. The system is designed to support decision makers in their search for practical lighting arrangements that provide various tradeoffs among these four conflicting objectives. Five decision variables are optimized in the present system, namely: number of lighting equipment, equipment positioning, mounting height, aiming angle, and rotation angle. The system is also designed to consider and satisfy all practical constraints that can be encountered in this lighting design problem. An application example is analyzed to illustrate the use of the system and demonstrate its capabilities in generating near optimal and practical lighting arrangements for nighttime highway construction projects.  相似文献   

11.
In the United States, public agencies are adopting the design-build (DB) delivery method for delivering highway projects after having used the traditional design-bid-build method for generations. In the 2002 design-build contracting final rule, the Federal Highway Administration (FHWA) strongly encourages the use of two-phase selection procedures for DB procurement. This paper takes a case study approach to investigating the use of a two-phase process for selecting providers of highway design-build services. Using two DB projects in central Texas as case studies, the writers have analyzed project documentation and performed interviews with 37 project participants involved in procurement, including owner representatives and legal consultants. For the first case, the writers selected the $1.3 billion SH-130 tolled expressway project in central Texas. Procurement of the SH-130 DB contract was performed before the FHWA rule on DB contracting was released. In addition, the writers examined procurement activities for the $154 million DB contract for the SH-45 SE tolled expressway, which was procured by the same owner in 2004 following procedures identified in the FHWA rule. As a result, a process was developed that included activities to be performed between the delivery method decision and the contract execution. This process model tracks the differences between the SH-130 and the SH-45 SE processes that are attributable to the latter’s adoption of the FHWA Rule.  相似文献   

12.
Time, cost and quality are the three factors that play a significant role in the planning and controlling of construction projects. The main barriers for their achievement are the changes in the project environment necessitating cost, time, and quality trade-offs. Literature has mainly focused on analyzing time and cost with little or no reported research focusing on models for optimizing construction time, cost, and quality jointly. Government agencies have recently started using new types of contracting methods which have placed an increasing pressure on decision makers in the construction industry to search for an optimal/near optimal resource utilization plan that minimizes construction cost and time while maximizing its quality. In this paper, a 0-1 Integer Programming model which enables meeting quality output standards and time and budget objectives respectively is developed. The clever use of binary variables allows us to solve many interesting and difficult problems and our ability to model complex problems increases tremendously when we use binary variables. A version of the model to minimize time meeting quality and cost objectives is applied to a road building project. Two alternatives versions of the model which enable to minimize cost meeting quality and time and to maximize quality meeting time and cost, are shown in an Appendix.  相似文献   

13.
In the process of decision making for design and execution of highway construction projects, long‐range cost forecasting is one of the most significant and complicated problems. This paper describes the development of a model that enables the user to make long‐range cost projections, taking into consideration general characteristics of the highway construction industry, as well as pertinent local conditions. The model presented uses conventional statistical methods to represent the main categories of typical jobs in the highway construction industry. From these categories, a composite model is created by assigning different weights to the input elements costs and then choosing a series of indicators to predict price trends for each separate element of the composite model. Use of this model reveals that bid volume in a certain area is a factor that has significant influence upon cost forecasts. This paper is accompanied by a case study based on actual data from highway construction projects performed for the Florida Department of Transportation in the years 1968–1981.  相似文献   

14.
This paper presents a decision support tool that is intended to help highway agencies in evaluating the suitability of nighttime construction for highway projects. This tool was developed as part of a research project sponsored by the Illinois Department of Transportation. The tool is a simple software package that was developed using a Microsoft Excel spreadsheet and Visual Basic for Applications. The proposed tool utilizes the cost-effectiveness analysis as a basis for comparison between daytime and nighttime operations. The proposed tool is mainly used whenever night shift is thought of as an alternative to the conventional daytime shift. Nonetheless, the tool is also generic in the sense that it can be used to compare different alternative plans such as different lane closure strategies or scheduling alternatives.  相似文献   

15.
The adjustment of utilities prior to highway construction is a particularly complex and challenging operation. One strategy that has been adopted in the last two decades is to incorporate utility adjustment work into highway construction contracts. In theory, this approach eliminates or reduces some of the complications and risks of utility adjustments. This paper aims to identify and analyze the decision drivers for selecting this strategy and help alleviate its implementation challenges. To this end, a comprehensive literature review and several interviews with experts from state departments of transportation and utility companies were conducted. Assessment surveys regarding the performance of recent projects that used the combined strategy were performed. Conclusions and recommendations for future research are presented.  相似文献   

16.
Although geographic information systems (GISs) have been applied in different areas of transportation, full use of their potential in speed profile analysis and highway design consistency studies has yet to be made. The possibilities that GISs offer for analysis and the increasing number of highway inventories supported by such systems, including traffic data and crash rates, suggest that the implementation of a highway design consistency analysis module within a GIS will facilitate and improve road safety studies. It is with this aim that a GIS-based computer system that builds vehicle speed profiles and analyzes highway design consistency has been developed, in which an operating speed prediction model, acceleration/deceleration rates, and other features can be configured by the engineering user in order to obtain an analysis that is more representative of drivers and local conditions. Application of this system to the study of the design consistency of highways is described, using three examples.  相似文献   

17.
18.
The ongoing plethora of rehabilitation in the infrastructure domain requires more planning and integration during design and construction. To achieve this, there is a need for developing and using semantic (ontology-based) mechanisms for the exchange of development knowledge among all project stakeholders. This paper presents a distributed ontology architecture for knowledge management in highway construction. With every other utility tied to the highway geometry, the architecture is intended to be the base for a cross-discipline knowledge exchange in the infrastructure domain. The architecture presents highway knowledge on three levels: domain knowledge (an umbrella for infrastructure shared knowledge), application knowledge (representation of highway-specific knowledge), and user knowledge (an enterprise-specific representation of highway knowledge). The proposed architecture models highway concepts using six major root concepts: project, process, product, actor, resources, and technical topics (attributes and constraints). The architecture was developed using rigorous knowledge acquisition and ontology development techniques. It was developed as an extension for the e-COGNOS ontology. The architecture was validated through input from domain experts.  相似文献   

19.
An increasing volume of highway repair and construction work is being performed during the off-peak nighttime hours to mitigate the impact of construction-related daytime traffic congestions and shorten the duration of construction operations. The utilization and placement of light towers to illuminate the work zone in this type of construction can cause harmful levels of glare for both drivers and construction workers. This paper presents the results of field experiments which were conducted to (1) study the levels of glare and lighting performance generated by light towers in and around nighttime work zones; (2) analyze the combined impact of the light tower set up parameters including its height as well as its aiming and rotation angles on glare and lighting performance; and (3) provide practical recommendations to reduce and control lighting glare in and around nighttime work zones. The results of these experiments confirm that the set up of light towers has a significant impact on glare and therefore it should be carefully designed and executed on nighttime highway construction projects to ensure the safety of the traveling public as well as construction workers.  相似文献   

20.
Construction specifications are used by transportation agencies to define the client’s requirements of the final product. The primary motivation of adopting the newer end result specification (ERS) or performance related specification over method-based specification (MBS) is to reduce clients’ costs, encourage contractors’ innovation, and improve overall quality. However, some transportation agencies have been reluctant to fully implement ERS due to lack of demonstrated evidence on whether they achieve comparable level of quality or performance. This paper investigates if the specification type has any effect on quality. The case study presented is based on data from New Brunswick Department of Transportation (NBDOT) from years 2003–2007. NBDOT generally uses ERSs to call paving contracts equal to or larger than 8,000 t. MBSs are used for all other smaller paving contracts. The most prevalent indicator variables for accepting asphalt paving jobs in North America [that is, percent theoretical maximum relative density, asphalt binder content, air voids, voids in mineral aggregates, percent passing 4.75 mm (No. 4), and 75?μm (No. 200) sieves] were investigated. Statistical analysis was performed to compare the deviation of the quality indicator variables from their respective job mix formula values for paving projects that used MBS or ERS. ANOVA results revealed that there were no significant differences between the qualities achieved from the two specification types. Also, no significant differences were found from within-specification comparisons over the time frame examined. Given the possible cost advantages from agency’s point of view, the flexibility of the contractors to innovate and the fact that this study demonstrates quality is not compromised, there is an opportunity for agencies to expand or fully adopt the use of ERS specifications.  相似文献   

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