Environmental Considerations for a Proposed Tolled Highway Project

As federal dollars available for highway projects are tightened and as demand for more highway capacity continues to increase, transportation officials seek more innovative financing methods. One of the more common methods has been to toll new highway projects. Recently, tollways also have been considered for existing, free-access roadways, i.e., nontolled, infrastructure segments. Transportation planners must consider that this so-called “innovative” financing technique, i.e., the decision to toll existing and new roadways, is subject to provisions of the National Environmental Protection Act (NEPA). This renewed interest in tolling mandates that transportation planners revisit the requirements of NEPA, and in this context, its applicability to decisions to toll roads for financing of highway projects. NEPA requires that, prior to construction of a bridge or highway, the head of the federal agency that is committing funds to the project must evaluate the effect of the project on the human environment; the effect of the project on the habitat of an endangered species, which implicates provisions of the Endangered Species Act; the effect of the project on any historic properties in the vicinity of the project, which implicates provisions of the National Historic Preservation Act, and the effect of the project on minority or low-income-populations, called environmental justice, which implicates Title VI of the Civil Rights Act of 1964. In this paper, we analyze the requirements of NEPA as they relate to Title VI of the Civil Rights Act of 1964. The interrelation of the two acts now mandates that the transportation planner consider an environmental justice concept in planning for highway and bridge projects. The intent of this paper is to provide some guidance to transportation planners in light of the environmental justice issues implicated by Title VI of the Civil Rights Act of 1964 as they begin the planning stages for highway and bridge projects.     

Environmental Mandates for a Proposed Highway or Bridge Project When the Habitat of an Endangered Species and/or Historical Properties Are in the Vicinity

Prior to beginning a major highway or bridge project, the transportation planner must address requirements set out in the National Environmental Protection Act (NEPA). NEPA requires a specific evaluation of the effect a major highway or bridge project will have on the environment. This evaluation must include consideration of the effect the project may have on the habitat of an endangered species, which implicates provisions of the Endangered Species Act (ESA) and on historical properties in the vicinity of the project, which implicates provisions of the National Historic Preservation Act (NHPA). This paper presents requisites of NEPA that integrate the requirements of ESA and NHPA into the initial evaluation of the impact on the human environment of a major highway or bridge project. The intent of this paper is to provide guidance to transportation planners in light of NEPA, ESA, and NHPA statutes as they begin the planning stages for highway and bridge projects.     

Compliance Guide for a Proposed Highway Project to Meet National Environment Protection Act Requirements

The National Environmental Protection Act (NEPA) requires that, prior to construction of a highway, the head of the federal agency that is committing funds to the project must evaluate the effect of the project on the human environment; the effect of the project on the habitat of an endangered species, which implicates provisions of the Endangered Species Act, the effect of the project on any historic properties in the vicinity of the project, which implicates provisions of the National Historic Preservation Act, and the effect of the project on minority or low-income populations, called environmental justice, which implicates Title VI of the Civil Rights Act of 1964. In this paper, we provide an example guide for transportation planners to follow as they comply with NEPA and the related acts in the beginning planning stages for a highway project.     

Strategies for Planned Project Acceleration

Departments of transportation in the United States are under increasing pressure to accelerate projects to meet user-defined constraints and reduce the inconvenience to the traveling public. Although there is information about acceleration projects in other industries, there has been little specifically aimed at highway projects. A domestic scan sponsored by the National Cooperative Highway Research Program was tasked with providing information in this area. The objective of this paper is to synthesize the resulting information into fundamentals that support successful planned accelerated highway project delivery. Case studies of how departments of transportation successfully accelerated the construction of four very different projects in California, Florida, and Texas serve as the basis for identifying these fundamentals. The fundamentals include upfront and detailed planning, designs that facilitate accelerated construction, a collaborative environment for project stakeholders, and incentives and disincentives to motivate construction contractors.     

Concrete Bridge Demolition Methods and Equipment

The transportation infrastructure in the U.S. is maturing rather rapidly, leading to a shift of work and expenditures from new construction to maintenance, rehabilitation, retrofit, or even replacement of the existing system. Therefore, bridge demolition is increasingly becoming an important issue, as more bridges reach their service life and require rehabilitation or replacement. Furthermore, as the capacity of bridges and highways are reached, partial or total removal of bridges become necessary to allow for widening of the highway underneath the bridge or for widening the bridge itself to increase the capacity of the transportation system. Therefore, this paper addresses an important topic. It first discusses the factors affecting the selection of a bridge demolition technique. Then, the paper lists and describes a number of techniques and equipment employed in concrete bridge demolition along with discussions of actual bridge demolition projects and experiences. Finally, the paper outlines and discusses some safety issues related to the bridge demolition process.     

Legal Environment for Warranty Contracting

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.     

Evaluation of Risk Factors Leading to Cost Overrun in Delivery of Highway Construction Projects

Accurate owner budget estimates are critical to the initial decision-to-build process for highway construction projects. However, transportation projects have historically experienced significant construction cost overruns from the time the decision to build has been taken by the owner. This paper addresses the problem of why highway projects overrun their predicted costs. It identifies the owner risk variables that contribute to significant cost overrun and then uses factor analysis, expert elicitation, and the nominal group technique to establish groups of importance ranked owner risks. Stepwise multivariate regression analysis is also used to investigate any correlation of the percentage of cost overrun with risks, together with attributes such as highway project type, indexed cost, geographic location, and project delivery method. The research results indicate a correlation between the reciprocal of project budget size and percentage cost overrun. This can be useful for owners in determining more realistic decision-to-build highway budget estimates by taking into account the economies of scale associated with larger projects.     

Corridor Protection through NEPA

The addition of interchanges, traffic signals, or unsignalized driveways to an arterial corridor increases crash risk and decreases travel speeds. As adjacent vacant land is developed, however, private landowners often desire direct access to the arterial route. Because the Virginia Department of Transportation has the authority to allow direct access provided no immediate adverse impact would occur, arterials in high-growth areas tend to have an increasing number of intersections as demands for direct access grow. This study investigated the feasibility of using the provisions of the National Environmental Policy Act (NEPA) to limit corridor access (e.g., grade-separated interchanges or at-grade intersections) through four administrative mechanisms: (1) including the limited access requirement as a condition in the record of decision; (2) effecting a contract (the Federal-Aid Project Agreement) that stipulates limiting access as a requirement; (3) implementing a supplemental agreement between interested parties that indicates how the character of the corridor shall be maintained; and (4) documenting the corridor-preservation conditions that remove the requirement of an Environmental Impact Statement. Factors that limit the effectiveness of these mechanisms include (1) the source of funds for the project; (2) the extent to which environmental concerns remain constant after the NEPA process is concluded; (3) the willingness of agencies to exercise the authority they are accorded through NEPA-related agreements; and (4) the passage of congressional legislation that enhances or restricts the scope of NEPA. Case studies of projects in Virginia where the NEPA process has helped preserve the characteristics of corridors show that the process may serve to raise barriers to adding access points but does not guarantee that access points may never be added.     

Developing a Traffic Closure Integrated Linear Schedule for Highway Rehabilitation Projects

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.     

基于全生命周期的绿色公路建设分析

深度分析了国内外交通行业碳排放清单及碳排放因子目录,结合中国交通行业特点,基于现有的公路工程估算指标及中国传统交通行业施工机械设备台班单价计算表,总结归纳符合中国交通行业特点的碳排放因子数据. 基于归因全生命周期评价方法（ALCA）,采用“自下而上”的公路工程碳排放计量思路,将公路工程项目建设期内工程活动分为分项工程–分部工程–单位工程,建立了公路工程建设期碳排放数据库及碳排放测算模型. 在此基础上,利用MATLAB搭建了公路工程碳排放智能估算软件并对国内两段支线高速公路的路面工程碳排放进行了估算分析,实现了仅通过公路里程量、工程方量和公路等级等信息即可快速估算并统计碳排放量,同时能够智能溯源各阶段碳排放要素并定位碳排放大户,为交通行业节能减排提供数据和理论基础. 分析显示,在路面工程中,稳定土基层和沥青路面面层的碳排放主导整体碳排放量,占据了99.6%以上,其中,以C32.5水泥为主的材料占据了75%左右的碳排放.     

Optimum Planning of Highway Construction under A + B Bidding Method

In recent years, many departments of transportation in the United States have started to apply the A + B bidding method in highway projects in order to reduce construction time and minimize its associated traffic congestion and adverse impact on local economies. The application of this method places an increased pressure on contractors to minimize both the time and cost of highway construction. This paper presents a practical model for optimizing resource utilization in highway projects that utilize the A + B bidding method. The model is designed to minimize the total combined bid by identifying the optimum crew formation and the optimum level of crew work continuity for each activity in the project. The model is developed using a dynamic programming formulation and is incorporated in a Windows application that provides a user-friendly interface to facilitate the optimization analysis. An application example of a highway project is analyzed to illustrate the use of the model and to demonstrate its capabilities.     

Quantitative Methods for Design-Build Team Selection

The use of design/build (DB) contracting by transportation agencies has been steadily increasing as a project delivery system for large complex highway projects. However, moving to DB from traditional design-bid-build procurement can be a challenge. One significant barrier is gaining acceptance of a best-value selection process in which technical aspects of a proposal are considered separately and then combined with price to determine the winning proposal. These technical aspects mostly consist of qualitative criteria, thus making room for human errors or biases. Any perceived presence of bias or influence in the selection process can lead to public mistrust and protests by bidders. It is important that a rigorous quantitative mathematical analysis of the evaluation process be conducted to determine whether bias exists and to eliminate it. The paper discusses two potential sources of bias—evaluators and weighting model—in the DB selection process and presents mathematical models to detect and remove biases should they exist. A score normalization model deals with biases from the evaluators; then a graphical weight-space volume model and a Monte Carlo statistical sampling model are developed to remove biases from the weighting model. The models are then tested and demonstrated using results from the DB bridge replacement project for the collapsed Mississippi River bridge of Interstate 35W in Minneapolis.     

CONLIGHT: Lighting Design Model for Nighttime Highway Construction

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.     

Role of Workforce Management in Bridge Superstructure Labor Productivity

There have been many studies on different aspects of the construction process in regard to how they each impact construction productivity. In reviewing the documentation of this research, very few articles were located that dealt with heavy/highway construction in general, and even fewer were found that dealt with bridges in particular. In addition, very little was found in the literature dealing with the effect that the quality of workforce management has on construction productivity. This paper describes the results of four case studies of highway bridge construction performed by established contractors with little bridge building experience, in which workforce management had a significant negative effect on labor productivity. The contractors’ lack of experience in bridge construction seemed to be the cause of several problems that plagued each of the four projects. The baseline productivity of each project was calculated, and the loss of labor efficiency was estimated to be 80, 75, 32, and 70%, respectively. The schedule slippage on the four case study projects was estimated to be between 127 and 329%.     

Forecasting Construction Staffing for Transportation Agencies

When the volume of construction projects let to contract increases significantly, state departments of transportation must critically examine internal construction project management staffing capabilities and accurately forecast the manpower required to execute future projects. This paper describes the development of a model or process to forecast manpower requirements as a function of project type and cost for selected employee classifications. Using data from 130 recently completed highway construction projects and over 11,000 employee payroll entries, regression analysis plots were generated to predict overall manpower requirements for projects of a given type and cost. These overall requirements were then adjusted to predict manpower requirements for individual employee classifications using typical task allocation percentages obtained from questionnaire data. The output from the model serves as input into commercially available critical path method scheduling software to facilitate manpower planning and resource leveling.     

Relating Cost Growth from the Initial Estimate to Design Fee for Transportation Projects

Intuitively, there should be a relationship between the size of the design fee for a transportation project and the quality of the resulting design. This study sought that relationship by looking at the fee expressed as a percentage of the construction cost and the final construction cost growth from the engineer’s initial estimate of the construction cost at the time the design contract was awarded. The research team analyzed 31 projects from the Oklahoma Turnpike Authority with a total construction value of $90 million. The projects were divided into road and bridge projects. Based on the results of the analysis, it seems that as the design fee decreases, the absolute percentage of construction cost growth from the engineer’s early estimate increases. The relationship is strongest for bridge projects, which tend to be more technically complex to design than roadway projects. This confirms for U.S. projects the result of an earlier study in Saudi Arabia. This paper concludes that the design fee should be viewed as an investment at a point in time where the ability to impact the project is the highest and can accrue the benefit of reduced cost growth.     

Spread Footing Foundation for Highway Bridge Applications

Shallow spread footings on soil are becoming an attractive choice for supporting highway bridge structures. However, to encourage their utilization, well-documented, comprehensive case histories must be established and made accessible to practicing bridge and geotechnical engineers. In addition, performance prediction methods for spread footing foundations must be verified further using carefully compiled field data. This paper is the writers' attempt toward achieving these goals, presenting details of a recently completed research project on 30 bridge spread footings in Ohio. The project data show that spread footings can be used successfully to support highway bridge structures on both cohesionless and cohesive soils, provided that the subsoil conditions are suitable and that the existing performance prediction methods are accurate.     

Frequency of Change Orders in Highway Construction Using Alternate Count-Data Modeling Methods

A common problem at state transportation agencies is the inability to complete projects within the original scope of work. Change orders, which are contractual documents issued to accommodate the additional work in a contract, are generally due to root causes such as design errors, unexpected site conditions, and weather conditions, and intermediate causes such as bidding characteristics. At the preaward phase of project management, an improved understanding of the factors that are associated with change orders will be of value and also can serve as a basis for taking steps to reduce concomitant contractual aberrations such as time delay and cost overruns. Recognizing that the occurrence of change orders is a count variable, this paper analyzes the frequency of change orders using a variety of count-modeling methods including the negative binomial, Poisson, zero-inflated negative binomial, and zero-inflated Poisson. Using 5 years of contract data from Indiana highway projects, appropriate models are estimated to assess the influence of project type, contract type, project duration, and project cost on the frequency of change orders.     

Identification of Decision Drivers for the Strategy of Incorporating Utility Relocations into Highway Construction Contracts

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.