State-of-Practice Technologies on Accelerated Urban Highway Rehabilitation: I-15 California Experience

This case study paper presents an innovative fast-track approach applied to a heavily trafficked urban freeway reconstruction project in Southern California. Badly deteriorated truck lanes in both directions along a 4.5-km stretch of I-15 were rebuilt from the gravel base up. The operations, estimated to take 10?months using traditional nighttime closures, were completed in two 9-day continuous closures with round-the-clock (about 210?h for each direction) operations. This “Rapid Rehab” project adopted state-of-practice technologies to accelerate construction, mitigate traffic disruptions, and propagate project information. As a result, traffic demand through the construction work zone was reduced by 20% and the maximum peak-hour delay was reduced by 50%. The estimated benefits of accelerated reconstruction on this project included a 28% reduction in agency cost and 29% time value savings to road users, compared to the traditional approach of using repeated nighttime closures. Web surveys showed dramatic changes in public perception of the Rapid Rehab approach from initial reluctance and objection to positive support.     

Integrated Design/Construction/Operations Analysis for Fast-Track Urban Freeway Reconstruction

The California Department of Transportation is rehabilitating or reconstructing deteriorated urban freeways using long-life (30+ years) strategies. These pavements were constructed between 1955 and 1970 with design lives of 20 years. This paper summarizes preconstruction analysis of the fast-track pavement reconstruction on Interstate-15 (I-15) at Devore which used two one-roadbed continuous (about 210 h) closures with round-the-clock (24/7) operations. The integrated analysis concluded that the one-roadbed continuous closures are the most economical scenario when compared to traditional nighttime or weekend closures from the perspective of schedule, delay, and costs. The preconstruction was validated with as-built construction and traffic performances monitored during construction. The construction management plan—including contingency, incentives, and critical path method schedule—was developed utilizing the Construction Analysis for Pavement Rehabilitation Strategies (CA4PRS) computer model. The results of this planning study are useful for transportation agencies in developing highway rehabilitation strategies that balance the maximization of construction productivity with a minimization of traffic delay.     

Computer Simulation Model: Construction Analysis for Pavement Rehabilitation Strategies

Most state highways in the United States were built during the 1960s and 1970s with an infrastructure investment of more than $1 trillion. They now exceed their 20?year design lives and are seriously deteriorated. The consequences are high maintenance and road user costs because of degraded road surfaces and construction work zone delays. Efficient planning of highway rehabilitation closures is critical. This paper presents a simulation model, Construction Analysis for Pavement Rehabilitation Strategies (CA4PRS), which estimates the maximum amount of highway rehabilitation/reconstruction during various closure timeframes. The model balances project constraints such as scheduling interfaces, pavement materials and design, contractor logistics and resources, and traffic operations. It has been successfully used on several urban freeway rehabilitation projects with high traffic volume, including projects on I-10 and I-710. The CA4PRS helps agencies and contractors plan highway rehabilitation strategies by taking into account long-life pavement performance, construction productivity, traffic delay, and total cost.     

Case Study of Urban Concrete Pavement Reconstruction on Interstate 10

Many urban concrete pavements in California need to be reconstructed, as they have exceeded their design lives and require frequent maintenance and repair. Information is needed to determine which methodologies for pavement design, materials selection, traffic management, and reconstruction strategies are most suitable to achieve the objectives of California Department of Transportation’s (Caltrans) long-life pavement rehabilitation strategies (LLPRS) program. To develop construction productivity information for several construction windows, a case study was performed on a Caltrans concrete rehabilitation demonstration project near Los Angeles on Interstate-10, where 20 lane-km was successfully rebuilt using fast setting hydraulic cement concrete (FSHCC) with one weekend closure for 2.8 lane-km and repeated 7- and 10-h nighttime closures for the remaining distance. The concrete delivery and discharge controlled the overall progress. In terms of the number of slabs replaced per hour, the 55-h weekend closure was 54% faster than the average nighttime closure. An excellent traffic management strategy helped to reduce the volume of traffic during the weekend closure and minimize the traffic delay through the construction zone.     

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.     

Partnering Process Model for Public-Sector Fast-Track Design-Build Projects in Korea

The use of design-build project delivery in the public sector has increased rapidly since the early 1990s due to its advantages over traditional delivery methods, particularly in terms of shortening the overall project duration. Fast-track approaches are being applied to design-build projects to achieve the optimum schedule durations. While both fast-track projects and design-build project have been researched separately in the past, there is little published research on how they are truly integrated. Likewise, the research has shown the merits of partnering in design-build and fast-track projects separately, but not in an integrated model. The purpose of this study is to develop a fast-track partnering process model (FTPPM) that combines the fast-track approach with the partnering concept. The model is based on the analysis of the factors that influence successful fast-track processes. Seven key success vehicles were discovered using the factor analysis method. The FTPPM is composed of the preparation stage, the fast-track workshop stage, and the detailed design and construction stage. The activities for each stage for fast-track implementation are developed in consideration with seven key success vehicles for fast-track projects.     

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.     

Weekend Closure for Construction of Asphalt Overlay on Urban Highway

Construction of asphalt overlays for urban highways is generally restricted to off-peak hours, often exclusively nighttime hours, and to partial closures to minimize public inconvenience. Such constraints are thought to adversely affect production and quality. In August 1997, the Washington State Department of Transportation implemented a pilot project to evaluate the option of a full weekend closure—closure of all lanes in a single direction throughout designated weekend hours—as an alternative to nighttime closures. Two concerns were consistent construction quality between nighttime and daytime paving and general comparison of the full weekend closure with other closure strategies. Surface smoothness (rideability) and in-place density were compared between nighttime and daytime mainline paving for this project, and gradation and asphalt cement content variabilities were compared with published average values. Production rates were compared to those from a comparably sized nighttime project. The investigation revealed that consistent quality, exceeding reported average values, may be achieved. High paving production rates resulted from close proximity of the hot mix plant to the work zone.     

Accuracy of Highway Contractor’s Schedules

Contractors are required by the Michigan Department of Transportation (MDOT) to submit a progress schedule identifying the controlling path of activities for a construction project. During the 2000 construction season, MDOT allowed contractors to submit a progress schedule with overlapping or concurrent controlling operations. Prior to this, only one activity at a time could be controlling on the progress schedule. This paper reports on the results of a research project where the focus was to examine the accuracy of the progress schedules, which only list controlling items. Eight construction projects were studied and a determination of progress schedule accuracy was made. This was done to determine if there was an increase in accuracy of the schedules when concurrent controlling operations were used. Included in the eight projects were four without concurrent controlling activities and four with concurrent controlling activities. A comparison based upon similar projects with and without concurrent activities was made. Additionally, 22 projects were analyzed, all without concurrent controlling activities, to determine the accuracy of progress schedules for two types of projects. The comparison revealed that, in three of the four cases, the accuracy of progress schedules increased with the allowance of concurrent controlling activities. The 22 projects revealed that the accuracy of progress schedules varied considerably. It was also determined that contractors overestimated the duration of activities included in progress schedules.     

Crew Production Rates for Contract Time Estimation: Beam Erection, Deck, and Rail of Highway Bridges

Both the importance and process of estimating highway construction time have increased in significance as roadway user costs themselves have become more significant. In estimating construction time, few parameters are more significant than work item crew production rates and factors significantly affecting those rates. A standardized data collection tool was used to acquire a total of 67 data points from 25 ongoing Texas highway projects between February 2002 and May 2004, for three selected critical work items: beam erection, bridge deck, and bridge rail. With the data, several hypothesized drivers of the crew production rates were analyzed. While the factor of shape of deck (straight versus curved) was identified as a statistically significant driver of bridge deck crew production rate, no statistically significant drivers were found for work items of beam erection and bridge rail. The study also found that both formwork and rebarwork crew sizes have significant relationships with bridge deck production rate. Findings from this study will enable highway agencies to enhance accuracy of contract time estimation for highway bridge construction. The methodology for obtaining field-based production rates will also be beneficial for future researchers.     

Linear Scheduling Model with Varying Production Rates

Activity production rates drive the development and accuracy of linear schedules. The nature of linear projects dictates an assortment of variables that affect each activity’s production rate. The purpose of this research was to expand the capabilities of linear scheduling to account for variance in production rates when and where the variance occurs and to enhance the visual capabilities of linear scheduling. This new linear scheduling model, a linear scheduling model with varying production rates (LSMVPR), has two objectives. The first is to outline a framework to apply changes in production rates when and where they occur along the horizontal alignment of the project. The second objective is to illustrate the difficulty or ease of construction through the time-location chart. This research showed that the changes in production rates because of time and location can be modeled for use in predicting future construction projects. Using the concept of working windows, LSMVPR allows the scheduler to develop schedule durations on the basis of minimal project information. The model also allows the scheduler to analyze the impact of various routes or start dates for construction and the corresponding impact on the schedule. The graphical format allows the construction team to visualize the obstacles in the project when and where they occur by using a new feature called the activity performance index (API). This index is used to shade the linear scheduling chart by time and location with the variation in color indicating the variance in predicted production rate from the desired production rate.     

Production Equations for Unsteady-State Construction Processes

The production equation called Little’s law has been applied to construction data recently. However, Little’s law was derived for steady-state conditions assuming constant input and output rates and long production runs. Production in construction is inherently temporary, and learning curves and environmental influences often render input and output rates unequal and nonlinear. Starting with a conservation of mass formulation, general equations for work-in-process and cycle time for unsteady-state conditions and limited run production are developed. The motivation behind these equations is to explain common trends in production variables seen on construction projects. Previous studies have shown that when output from a construction production system is drastically increased, a significant upward impact is also seen on cycle time and work-in-process, and this work provides underlying theory and equations to explain these trends. Cycle time and work-in-process equations are presented as functions of time and on average. Data from construction activities are used to show that unsteady-state conditions commonly occur. Reasonable simplifications of the general equations provide guidelines for buffer sizing and resource allocation decisions.     

Developing a Decision Support Tool for Nighttime Construction in Highway Projects

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.     

Role of Inventory Buffers in Construction Labor Performance

Buffers of material stockpile (inventory) are formed at the work level in construction to help manage production. The size of material stockpiles often has an important bearing on construction project performance. In construction projects, where conditions are often uncertain and variable, some have suggested that buffers be sized and located according to the conditions. New management thinking like lean construction and theory of constraints suggests that the size of buffers needs to be managed carefully, because when oversized, buffers are wasteful, impede workflow, and hinder performance. Research has shown that project variability can be affected with the careful deployment of buffers but has not really evaluated the impact on construction labor performance. This paper reports an exploratory analysis of the relationship between inventory (buffers) and construction labor performance with data collected from three commercial projects in Brazil. In this study, the size of the buffer between rebar fabrication and installation in the construction of a structural system is compared to the labor performance of the fabrication and installation crews. The results show that some buffer helps achieve the best labor performance in the construction operations studied.     

Urban Freeway Bridge Reconstruction Planning: Case of Mockingbird Bridge

Urban freeway bridge reconstruction is a challenging process. Sites are often located in heavily populated areas and are always congested with traffic and construction activities. Lack of adequate planning on such projects can result in tremendous waste in project cost and schedule, traffic flow efficiency, and most importantly, safety to both the traveling public and construction crews. Accordingly, a need exists to develop techniques to help plan and construct urban bridge projects more effectively. This paper documents the process of replanning a bridge project, Mockingbird Bridge. The case describes a research effort that beneficially applied several construction engineering concepts to the project. For the project, the research resulted in sizable savings in cost and duration. For the industry, the case resulted in several lessons for future projects. Among these, the primary lesson is that the integration of bridge reconstruction sequence, constructability, and traffic control plans is crucial to project success.     

Automated Generation of Customized Field Data Collection Templates to Support Information Needs of Cost Estimators

While estimating activity production rates, cost estimators rely on historical production rates. To have realistic and useful cost estimates based on historical production rates, such production rate data should be augmented with historical contextual information that depict conditions under which activity production rates were achieved in past projects. This information is needed in determining which production rate to use among alternates for a similar activity existing in a new bid. Estimators need contextual information especially when they are unfamiliar with the work being estimated. Hence, such information items need to be identified, collected, and stored for estimators’ use in new projects. This paper details a construction-method specific and an extensible approach that is developed for enabling cost estimators to define contextual information items that need to be collected on job sites and stored as part of project histories. Based on this approach, the writers implemented a prototype system, called as ContextGen, and performed user-tests with estimators with different experience levels. Results showed that the developed approach captures method-specific information needs of estimators and is extensible to incorporate new contextual information items that can have different data representations. The developed approach is also precise in retrieving contextual information items specific to a construction method from a set of predefined contextual information items available in a library.     

Using GPS to Measure the Impact of Construction Activities on Rural Interstates

The presence of construction work zones on interstates impacts the traveling conditions encountered by motorists. These changes not only affect the traveling public, but also the workers that perform the construction. The impacts of the work being performed also tend to cause queuing. In addition, these periods of construction operations have been linked to an increase in the number of accidents and fatalities that involve road-users and construction crews. A research project was undertaken to evaluate possible options to improve the safety of construction work zones on interstates in the state of Indiana. One component of this project dealt with the use of the Global Positioning System (GPS) to collect traffic data and to relate the traveling conditions encountered with the differing construction activities taking place. This paper describes the GPS study conducted in three different rural work zones on Interstate 65 in Indiana. Multiple runs were conducted at each location to analyze the impact of traveling conditions to changes in lane restrictions during construction periods on traveling conditions.     

Empire State Building Project: Archetype of “Mass Construction”

Analysis of historical projects, with the dual benefits of hindsight and modern concepts of construction systems, can help fill the gaps in our theoretical understanding of production in construction, which have increasingly been identified as a barrier to progress in improving construction project management. The richness of the historical record describing construction of the Empire State Building provides a unique opportunity to analyze and compare it with the paradigms of craft, industrialized, and lean construction. Its size and its record rate of construction, which has not been broken since for tall buildings, make it of prime interest. The project progress was reconstructed using line-of-balance software and its different flows were assessed. The results lead to the conclusion that it is an archetypal example of what we propose be called “mass construction.” This enables a richer understanding of the taxonomy of production systems in construction, and should aid theoreticians and practitioners alike to devise better production systems for construction projects.     

Innovations in Nuclear Concrete Construction

The technical requirements and scope of concrete work on nuclear projects present significant engineering and construction challenges. These demands represent the extremes in many areas of construction operations. In meeting these challenges, engineering and construction forces have developed several innovations which can be beneficially applied to other types of construction. Innovative approaches in the general categories of engineering scope, construction input to engineering, work planning, special methods and techniques, and satisfaction of quality assurance requirements are given in this paper. The transfer of this technology to other segments of the construction industry will improve overall performance by avoiding the problem areas encountered on nuclear projects.     

Impact of Annual Average Daily Traffic on Highway Runoff Pollutant Concentrations

The objective of this study was to evaluate correlations between annual average daily traffic (AADT) and storm water runoff pollutant concentrations generated from California Department of Transportation (Caltrans) highway sites. Analyses of data collected from the Caltrans four-year (1997–2001) highway runoff characterization program revealed that, in general, pollutant concentrations from urban highways were higher than those found from nonurban highways. For a limited number of pollutants, however, the concentrations from nonurban highways were found to be higher than the concentrations from urban highways. No direct linear correlation was found between highway runoff pollutant event mean concentrations and AADT. However, through multiple regression analyses, it was shown that AADT has an influence on most highway runoff constituent concentrations, in conjunction with factors associated with watershed characteristics and pollutant build-up and wash off. The other noticeable factors shown to influence the accumulation of pollutants on highways were antecedent dry period, drainage area, maximum rain intensity, and land use.